Almost anything first person. It makes me incredibly nauseous, which is really unfortunate because there are some really neat games that use the mechanic. I recently sold my copy of Echo Night since I couldn't play for more than around ten minutes at a time. I also couldn't complete the tutorial in Half-Life because it made me so nauseous that I had to spend almost the entire day in bed. Weirdly I'm perfectly fine with Metroid Prime.