I am looking to buy my next set of quests and am not sure which route to take. This is what i have :

Core Set - two great solo quests

Mirkwood - very enjoyable and mostly solo-able with one or two tweaks

Khazad Dum & Dwarrowdelf - the high point of the game for me so far

Isengaard & Ringmaker - the low point of the game in terms of fiddly mechanics (time) and almost impossible difficulty level to beat solo

Black Riders - good box and very solo friendly

Hobbits - not very solo friendly and mostly frustrating quests

I wasnt very interested in Numenor as a theme. So i am left with Lost Realms and the Cycle or Grey Havens and the cycle. I do not want everything too difficult and fiddly like Ringmaker or puzzle based as i prefer having adventures.

I would really like a good undead exploration quest - now there are a few undead quests but i am not sure which ones are any good.

Is Temple of the Deceived the most dungeon crawl style undead quest as that and Drowned Ruins looks quite adventure based.

Flame of the West may be a good box - i certainly like the tactics hero so that is tempting and it does have undead as well in it.

Mount Gram escape seems to be a good quest at the not too difficult level and this cycle also has undead in it.

Any thoughts especially on the best undead adventure quest will be appreciated - if i can find the best undead adventure quest i may use that to move into a cycle.

Here's the various undead quests sorted into quests I really like, quests that are decent and ones that I don't particularly like or enjoy:

Great Undead Quests:

-The Dead Marshes. I am mainly referring to the nightmare version so if you aren't interested in nightmare this might not be applicable but the nightmare version of this quest has great undead enemies with some of the best art in the game for these sorts of foes. The undead in this quest are really unique and have various nasty effects or mechanics as well as very different stats. Some undead quests have enemies with very similar stats so it is nice to see quite a variance in this quest.

Due to this being such an early quest in the first cycle the nightmare version really isn't THAT tough so I highly recommend this quest if you are game!
-The Three Trials is one of my favorite quests in the game so it is instantly one of the best undead quests to me as well. Only issue; it is only sort of an undead quest. Yes the enemies are undead but they are very different from the rest of the undead in this game and are Dunlending Guardian Spirits. There are also only 3 of them. If this is enough to qualify as an undead quest to you though this is another highly recommended quest. Great mechanics, somewhat hard but not stupid hard and quite fun. Its also quite neat to do the different versions of Stage 2 in a random order instead of a chosen one as this usually makes the quest a little harder which is nice if you are running strong decks or just want more of a challenge on a particular attempt.

-Fate of Numenor is a really fun albeit fairly easy quest. While it isn't really that difficult this is one of my favourite newer quests. I love the locations that are double sided, I love the various quest stage mechanics and I love the theme and mechanics of the various enemies and treacheries. Also I love that in this quest you can randomly go from having just a few undead enemies in play to several appearing out of nowhere and having to then deal with a horde of them. Now Dread Realm, Treachery of Rhuadar and Dead Men's Dike all have the Cursed Dead enemy and Dead Lord enemy which also have similar effects of making several undead enemies enter play at once. The way that these quests do it mainly through Cursed Dead's ability is not anywhere near as cool or interesting though and actually ends up being somewhat frustrating to me. There is far less diversity as well as instead of differing enemies you are instead just facing several copies of Cursed Dead...

-Passage across the Marshes is my last choice for the best undead quests but it is a saga quest so isn't as easy to just buy and jump in. It is more fun in Campaign mode (I don't really play saga quests outside of saga/campaign mode at all so I am somewhat biased in this regard) which requires that you have all the prior Saga boxes so this might not be an option for you right at the moment. I love the mechanics with Smeagol, the nasty mire effects on locations can be brutal and the undead enemies in this quest have amazing art just like the enemies from dead marshes, which is set in the exact same location so they are the same unique type of undead enemy that inhabit that area (fallen elves and men during the War of the Last Alliance). Really like this quest and it is probably among my favorite saga quests even though it is really not a very exciting one!

Decent Undead Quests:
-Treachery of Rhuadar only just makes this list and I almost included it in the mediocre quests. It is actally a pretty solid quest and very unique quest but for some reason is just really forgettable for me. It even has great replayability as you can keep trying until you are able to explore all three side quests or alternatively you can attempt to beat it after only clearing one or none at all for a challenge. The enemies are not overly exciting however and the two new enemies (this quest features Cursed Dead and Dead Lord like Deadman's Dike and Dread Realm) unique to this scenario have more or less the exact same art and very similar stats. The boss is also Thaurdir once again (like deadman's dike and Carn Dum...).
Perhaps because it is like a less exciting less hard version of Deadman's Dike and Carn Dum is why it is a forgettable/rarely played quest for me... Either way a very decent quest but just not one that stands out to me at all.
-The Passing of the Grey Company. I have only played this quest once but had a blast playing it. Seems like it could get frustrating with certain decks however because of the CONSTANT threat gain from pretty much each and every encounter card. Really cool art and mechanics and it perfectly captures this part of the narrative. Some of the best art for undead enemies is definitely in this quest and the Army of the Dead boss at the end has both great art and is a fun boss enemy. The unique mechanic of this quest that turns damage from enemy attacks into threat (until a certain point!) is also really clever and a thematic home run.

This quest is great but very threat intensive and again like Passage of the Marshes is a Saga quest so requires every Saga box before it if you want to play Campaign mode but can always be played standalone without prior deluxe boxes. You probably need a pretty decent player card pool to beat this one as it isn't overly hard but I may have just gotten lucky on my first attempt/raced through fast enough. There are definitely some very nasty effects and without low starting threat decks and/or plenty of threat reduction you will not stand much of a chance against this one.
-Deadman's Dike is a pretty cool quest but is quite difficult. The whole Cursed Dead horde as I mentioned above can be a fairly frustrating encounter card. The mechanics and theme of the undead enemies in this quest are actually pretty great but there are so many moving parts and effects in this quest that you have to keep track of that it gets a bit tedious. This combined with the difficultly makes me avoid this quest fairly often and I rarely go back to play it. This quest is included in a great deluxe box though and once again I am somewhat biased as I play two handed and with real cards so any quests with more moving parts than usual are normally not among my favorites automatically just because of how fiddly they can be for me. Definitely a cool quest but fairly difficult and fiddly and just not as good as others.

Mediocre Undead Quests
-The Dream Realm. Great art, great mechanics and great theme but stupidly difficult... I pretty much NEVER have fun playing this quest. If you aren't running some very specific types of cards (like direct damage...) there is a good chance you will never be able to damage Daechannar as sorcery cards appear almost every round.... Then even after beating him you get a super grueling stage 3 that can easily kill multiple characters or heroes at the end of each round. If you want a truly punishing and difficult quest then the dream realm might be a good choice but with the amount of packs you do not have I think this would be a seriously punishing quest for you. I have all player cards that are out at this point in time and it is still one hell of a punishing quest for me!!!

Also most of the undead enemies in this quest are actually the "reanimated dead" enemies which are just player cards turned over. The few undead enemies unique to this quest that do have encounter cards however like Dwimmerlaik and Wraith of Carn Dum have EPIC art and really cool mechanics.

-Battle of Carn Dum. This one isn't really an undead quest as the only undead enemy is the boss Thaurdir. He is in the entire quest from the first turn to the last however so there is always an undead enemy around. This is no jokes probably my most hated quest of this entire game. I actually don't think I can even think of another quest that I legitimately hate. It is STUPIDLY hard, not fun at all and punishing in a way that just frustrates and annoys me rather than challenging or testing me. One day I will come back to this quest.... one day but not for a very long time.... I actually highly recommended against this quest.

Fog on the Barrow Downs is worth a mention, whilst none of the enemies actually feature the undead trait they are most definitely undead enemies (Wights). I would include this quest in the Great Undead Quests list as it is an absolutely fantastic quest. The only SINGLE thing I don't enjoy in this quest is the copies of Great Barrow at the end.... I really don't think that every copy should be shuffled into the encounter deck. It is so frustrating and stupid to have to explore like 3+ Great Barrows. There should be the one compulsory one and like ONE or maybe two absolute tops additional copies that are shuffled into the encounter deck. Pretty much the name of the game on stage 3 is explore the first Great Barrow as fast as possible and pray to Eru that you don't see another 3 copies appear before you win. I would honestly even prefer that each player is forced to clear one copy of Great Barrow each as the vast majority of times I play this quest more than 2 copies appear and I am not sure if I have ever played this quest and only encountered a single copy. If I have I certainly can't remember!

Finally I actually haven't played Temple of the Deceived yet.. I have the actual pack but just haven't attempted the quest as of yet so I can't really comment on this one.
Obviously this is all just purely my opinion and others will have very different ones but I hope that my breakdown was of some help and sheds some light on the subject for you! =)

The Three Trials sounds like a perfect fit to me.

Yeah if I had to choose just one or two it would be The Three Trials/Fate of Numenor.

Wow thanks for taking time to write such a comprehensive reply.

I do have 3 trials and really liked its artwork and theme, but it is extremely hard (at least to me) to defeat with a single deck especially the time mechanic and then all the guardians coming back at the end. So i do have this one already but have never beaten it properly.

I am looking for a searching adventure theme of sorts, hard to explain but like the Long Dark or Journey down the Anduin where you are moving through a set but with Undead monsters, the perfect scenario would be searching through a tomb or ruins location to find an objective or defeat a boss and having to defeat the undead that you meet. However nothing too hard or fiddly is preferred. I am not asking much !!

I will take on board the comments about Dread Realm and Deadmans Dike - if you think these are harder than 3 trials then i will probably leave them well alone. This assumed at least leans me away from Lost Realms (which sounds like it got a tough difficulty level generally) and into Grey Havens box as this has Fate of Numenor and then the continuing cycle has the interesting Temple of the Deceived, plus the Drowned Ruins looks like one i would enjoy, and maybe Thing in the Depths. So some additional mileage to be had here.

But i may first just reach for Flame of the West as it has a tactics hero i really want to use, a decent undead quest and i gather quite a good siege style quest too. I dont mind building a deck to combat threat, that is a better challenge that the nasty time triggers in Ringmaker that really annoy me. I am also happy getting one or two saga boxes (i do have Black Riders), i am not bothered about the campaign as such and am happy to play quests as one offs.

Before i buy though i will consider anything else anyone adds first.

In order of preference :

- The Treachery of Rhudaur (4th quest of Angamer Awakened cycle)

- The Dread Realm (6th quest of Angmar Awakened cycle)

- Deadman's dike (3rd quest of the Lost Realm deluxe box)

- The three Trials (2nd quest of Ringmaker cycle)

- Fate of Numenor (2nd quest of The Grey heavens delubuxe box)

- The Temple of deceived (3rd quest of DreamChaser cycle)

- Stone of Erech (POD)

- Fog on barrowdown (POD)

- Dead marshes (5th quest of the Shadows mirkwood cycle)

- Passage accross de the marshes (1st of the Land of Shadows saga box)

I am looking for a searching adventure theme of sorts, hard to explain but like the Long Dark or Journey down the Anduin where you are moving through a set but with Undead monsters, the perfect scenario would be searching through a tomb or ruins location to find an objective or defeat a boss and having to defeat the undead that you meet. However nothing too hard or fiddly is preferred. I am not asking much !!

Sounds like you'd like the Grey Havens + Dreamchaser undead quests; you pretty much described Temple of the Deceived right there, but replace "ruins location" with "jungle full of ruins".

The Drowned Ruins will also suit your tastes.