I guess the only type of level that I don't like making are castle levels and perhaps forest levels.
I do like making typical levels like grassland-type levels, water levels, underwater levels, and ice levels. But I'm also pretty good at making athletic-type levels, and odd stuff like space levels and stuff.
My favorite type of levels are overworld, snow, sky, underwater, hellish-like levels (you know, like Norfair or something), genuine castles and tanks. They're epic.
The least favorite or should I say... HATE, is PIPE MAZES! Men they're annoying.