Although a lot of people hate them immensly, I always like desert levels because they usually tend to be the biggest stages in any game they're featured in, and they always seem to be dev team playgrounds (secret areas, freedom of movement, gimmicks, etc.) I'm also a fan of high elevation stages (Hill Top from Sonic 2 comes to mind)
Can't stand lake/water or volcano stages where these locations are usually where devs put all of the "instant kill" crap at and I usually suck at avoiding pits when I'm in a rush
Can't stand lake/water or volcano stages where these locations are usually where devs put all of the "instant kill" crap at and I usually suck at avoiding pits when I'm in a rush