I think I might need to broaden my gaming horizons...
11 What post-apocalyptic RPG have you enjoyed most? Why?
I've never played in a post-apocalyptic RPG.
12 What humorous RPG have you enjoyed most? Give details.
I've never played in a humorous RPG.
13 What horror RPG have you enjoyed most? Why?
Call of Cthulu, because you get to play an average person struggling against invincible supernatural horrors.
14 What historical or cultural RPG have you enjoyed most? Give details.
Pendragon was fun, though I've only played it a few times. I enjoyed the different aspects of character creation--the "alignment" system was interesting. Also, I just enjoy Arthurian legend and Pendragon captured the spirit of those legends.
15 What pseudo or alternate history RPG have you enjoyed most? Why?
Cthulu Dark Ages. Because it mixes Cthulu with medieval history!
16 Which RPG besides D&D has the best magic system? Give details.
Mage: The Ascension. It encouraged players to be inventive about the spells they cast. The spells weren't cut-and-dried and where limited only by the imagination of the player--and paradox.
17 Which RPG has the best high tech rules? Why?
Rifts, maybe. If not then it seems like it has the most.
18 What is the crunchiest RPG you have played? Was it enjoyable?
Middle Earth Role Playing was a lot of fun. I would never try Rolemaster.
19 What is the fluffiest RPG you have played? Was it enjoyable?
I really don't like the terms "fluff" and "crunch."
20 Which setting have you enjoyed most? Why?
Outside D&D? World of Darkness, I guess.
My earlier answers to these questions can be found here.