by lorien4
Arkham Horror is the best. It is co -op adventure, has the most options for the players, it has replayability, but it is really much more complex than Ravenloft and can take 3 hours or even more. Once you are Ok with the rules, it shines, plus there are a lot of expansions. In a thread I read "consider AH as a horror film in a box".Ravenloft is a very good co-op dungeon crawler. It will give you a blast in the start, it is very random and has replayability. The only thing I don't like is that the scenarios are too limited (although there are lots of scenarios and heroes made by the fans, ChromaticDragon, I mean you :p). There is a mini-expansion "Dungeon Command Curse of Undeath", but not one I would really like. Don't misunderstand me, it has given me many hours of fun and it's short up to 90 minutes.
I don't own Descent, but from what I see it is a dungeon crawler with much more depth than Ravenloft. The Heroes play against another player and the game can drag very long.
You should also check Runebound.