My friend and I are heavy Arkham Horror fans. We play a lot. We tend to actually annoy our other friends by how much we want to play. But all-night Arkham Horror sessions are not uncommon for us, in fact they're the norm. I tell you this so you'll understand where I'm coming from when I tell you that curently my friend and I are 6-2 down against the Innsmouth Horror Ancient Ones. And don't even ask about the Heralds ... ! *grrrr*
Bokrug: Out of all the new Ancient Ones, this guy proved to be the easiest for us. We managed to buy off all the Beings Of Ib before he woke up. although in order to do so I did break my personal rule about telling someone else what to do with their Investigator. But c'mon, if you've just read out to the table about how to buy off the Beings Of Ib and one Investigator just happens to be starting with 3 monster trophies and his player immediately, the instantly you stop talking, says he is going to go buy himself a blessing ... well, how would YOU react?
Chaugnar Faugn: We didn't do that badly against this guy. We managed to seal 4 gates but his "stirs in slumber" text is more annoying that we had anticipated it being. It meant that not all the Investigators could close a gate to R'lyeh. Their Fight and Lore each no higher than 4, the -3 from the gate and then the "stirs in his slumber" text. I'm not sure I'd go so far as to say it was devastating but it certainly contributed to him waking up sooner than I think he otherwise would have done. His Attack is annoying and meant nobody lasted more than 3 turns against him. Coupled with his "armour", it resulted in a defeat.
Cthugha: I was surprised by how well we did against this guy. At the start of the game I honestly thought he'd kick us so hard it wouldn't even be funny. And his limitations on spending movement points did turn out to be as nasty as feared but having said all that we still managed to seal him up. Just.
Ghatanothoa: After 5 turns, one Investigator finally decided to throw caution to the wind and pick up two Clue Tokens. It was the first time a Visage token had been drawn all game ... he was devoured. The second Visage token drawn in the game wasn't a problem. The third, devoured. Things kinda went down hill after that. Although I did keep a secondary running total during the Final Fight of all the successes he stopped and I worked out that we would have beaten him if not for his text about ignoring the first success. So although we lost, it wasn't our worst defeat, not be a long shot.
Nyogtha: The Tendril Of Nyogtha appeared only once in the entire game and was slapped down quite hard. Rather disappointing, really. And then we had appalling luck during the final fight. EVERY player, except one, got devoured the instant they were pulled underground. Would have liked to have seen more of his text during the game and less of his text during the Final Fight ... hopefully next time. :-)
Quachil Uttaus: *glares* This guy is just obscene.
Rhan-Tegoth: The luck we had against this guy pretty much summed up our luck throughout the entire series of games. He had 4 Cultists on him when he woke up and the lowest die rolled to see how much Stamina was lost was a 4. Four extra doom tokens due to Cultists drawn and 1 mythos card that added 2 doom tokens made sure we had NO chance of stopping him from waking up at all.
Zhar: The extra mythos card text is quite fun. Until we got to the issue about whether or not you roll doubles on the second mythos card, too. Potentially, 8 gates could open before you even start your first turn. In the end, we decided not to bother with that but he still woke up far too quickly all the same. So quickly that we didn't even have enough weapons and spells for everyone. But despite that we still managed to beat him once. It was just the second time that destroyed us.
Dagon and Hydra: First mythos card opened a gate on Devil Reef. Start the game, start moving. Second mythos card opened a gate on ... er, Devil Reef. 5 player game so 5 monsters added to Devil Reef. 3 of them move. The Deep One Rising Track is now already on 5. Third mythos card. Devil Reef. Movement ... Riiiiiight ... First Epic Fight Card? Sinister Plot. Draw Cthuhlu's Sinister Plot ... roll a dicem and subtract one of the result. That many Investigators are devoured. It was a 5 player game. Guess what was rolled? I'll give you a clue, it wasn't 1, 2, 3, 4 or 5.
The quickest game of Arkham Horror I have EVER seen ...

It was a good week hahaha