I like the anub-arak in hearth stone and patches in naxrammas
My favorite Naxxramas boss was Heigan the Unclean because of the Safety Dance.
Faerlina, I always wanted to just give her a hug but she didn't seem to take it well
i liked the four horsemen fight.
Has to be Patchwerk. In vanilla, when I played hunter, I loved the race to the #1 spot with him. Memories...
I loved Sapphiron :D
The Four Horsemen
Kel'Thuzad for sure. And Mr. Bigglesworth if that counts. :P
My favorite Naxx boss would have to be Gluth
Thaddius is fun.
Sapphiron was my favorite i loved being able to tell who had raid awareness by where the corpses were at.
I've always been a fan of Sapphiron (in WoW at least), the room is just too awesome looking.
Loatheb, farming grave moss was fun.
Thaddius! We have more of a love/hate relationship, though, I suppose.
Patchwerk! He is so funny. An he wants to play :D
Heigan for me! That dance was fun! My favorite part of naxx by far!
Four Horseman, hands down!
Heigan the Unclean - even though he was incredibly frustrating for me as a Mage, it was a fight like no other when Naxxramas was first released. His Hero Power in Hearthstone is very reminiscent of the Heigan dance!