well, my favorite map i've played would have to be the "They Hunger", actually thats a mod, but it does have maps in it!!
my favorite map i've made, well.. i dont have a favorite.
a map i'd like to see? well a resident evil hl map, y'know, if ya watched resident evil you'll know. where all the workers become zombies etc. etc.
or a resident evil HL Mod based on one of the RE PS2 Games, RE-O, RE1,2,3 ETC. That would be cool.