-Fallout 3 wowed me, shame it then bored me.
-Morrowind did the same (Obilivion was a miss), it was the first "big world" map game I had to explore. Saying that, once you've gotten used to exploring, the "big world" seems a lot smaller.
-Apocalyptica; some of the levels were beautiful when I first saw them. Same the game was disappointing.
-The Shadow the Hedghog level where your on the ark and its falling apart and your forced to deal with the games jump phyics. Thats one long fall if you miss... But one of the most nerve inducing levels I've ever played, I was literally biting my fingers nails praying that my next jump would make that black hedgehog live.
-Sonic again, chemical plant zone; how I hate your second level. Yet if I had to play any level of any sonic game all day, this is it.
-Doom's cyber demon arena grabbed horrible memories of RUNNING FOR MY LIFE... To this day the cyber demon has a place as my all time fav. boss in any game.