I hear a lot of talk about Big Boo's haunt in Super Mario 64, particularly the piano, but the stage doesn't really give me any unease, and I thought the chomping piano was hilarious.

For me, what does it is World 8 in Super Mario Bros. 3. Now, your opinion of this may change depending on what version you played first. Was it 16-bit? Then maybe it doesn't feel the same to you. A lot of dusky, blotted out mountain backgrounds and leafy jungle backgrounds. That's the problem with trying to graphically update everything. Some things should just be left as is. In the 8-bit version of this game, those stages were just black background, and much more bleak. At most, the actual stages halfway through world 8 had white outlines of background elements, sort of like what you'd see beyond the stage goals in some worlds. You couldn't even tell where the stage goal began, and the overworld music of course was replaced by the usual underground theme. Add to this a distinct lack of toad houses and bonus games? Yeah. Even better, World 8-2 was almost completely colorless, aside from enemies and quicksand. It was almost like the game was mocking previous lighter parts with this nightmare dream world.