I currently own the core set, all the expansions, and all the lieutenant packs, but I've never purchased any of the H&M packs and I'm wondering if there is a general consensus that certain ones are definite must buys compared to others. I realize this is probably all just a matter of opinion, as some will like certain heroes/monsters more than others, but I'm looking for some feedback from you guys. Thank you for your time.

I think it depends on your taste and desire of the game. For example, Crown of Destiny has big minis, while Bonds of Wild has lots of small minis.

My personal H&M buy order would be:

1) Treaty of Champions : It has very funny things for both: heroes and Overlord. The Crow Hags are quite powerful and strategically flexible (not to mention Death Omen will allow you to play with all those conditions as you like). Skeleton Archers are both resilient and strong, they fit very well with MoB and reanimates theme (undead army). Zyla is a very mobile mage (amazing for MoB) and may be un-targetable once per quest due to her Feat. Grey Ker is a good scout (good HP, high stamina and standard speed and attributes) very strategically too due to his abilities.

2) Bonds of Wilds : as an Overlord, you will like to swarm heroes with the Kobolds; and heroes will definitely learn about the use of familiars with this pack.

3) Crown of Destiny : I like the Chaos Beast minis, Giants have a very good crowd control due to stun + sweep; and the pack has Lindel, one of the best scouts (IMO) of the game.

4) Crusade of the Forgotten : Golems are my personal monsters for delaying heroes by blocking paths; Iron Skin is amazing for this monster once you have all the expansions. Astarra and Andira are powerful if used properly but also funny to play too.

5) Guardians of the Deephall : I like massive monsters (Crypt Dragon) and I think Wendigos are good. Mordog has been one of the most used warriors for my friend because he is a good tank. Also Silhoutte as a Treasure Hunter + Feat have changed many campaigns when I see her getting a treasure chest per quest in most of the cases.

Particular mention to Shards of Everdark , I would probably put it as an option 2, but because it is new, it can be difficult to get it. The monsters are very interesting to play (Ice Wyrms and Shades) and well, I always wanted to play Steelhorns as a hero.

If you still own the 1st edition and the conversion kit, you should look first at the H&M packs that comes with previously unreleased monsters, imo. I just like you, have anything but the H&M packs and thats what I'll do asap.

Ah yes the Crown of Destiny, one of my faves.

It's got both Lindel & Corbin for those that want to scratch that Legolas & Gimli itch. Thoe whole pack is really good imo.

Oath of the Outcast is also a good choice, Elder Mok and Trenloe the Strong are very good characters and imo Beastmen are criminally underrrated thanks to the master's Command ability.