Here's a list of games over the years where the graphics have impressed me.

• Doom 3: I remember seeing early screesnhots of the game and being absolutely amazed by it. When it was released and I played it I was stunned. When I got the game a few years back I used to play it on medium settings but even then I still thought it looked great. Of course, it's a very dark game but even now, the lighting effects still impress me.
• Far Cry: Another game I used to have to play on medium settings at the time. It was the water detail, lush jungles and draw distances that amazed me. I still love the games graphics because its so easy on the eyes thanks to the colourful landscape.
• Half-Life 2 and Source engine: I owned Doom 3 and Far Cry already but HL 2 took it to the extreme. I managed to play this on high with good frame rates even with my old GeForce FX5500 card. The lighting was better in Doom 3 and the vegetation better in Far Cry, but in terms of realism HL2 stole the show. The characters, textures and not to mention physics were just amazing. It had the best all-round engine and was the best game out of the 3. Still an excellent engine that Valve still uses today.
• The Chronicles Of Riddick Escape From Butcher Bay: I didnt get this until, like, 2 years after release. But the graphics were so damn good and compared to games of the year I bought it. Everything looks so gritty in a great way. The characters look amazing.
• F.E.A.R.: This is a great looking game too. The textures are good, the physics, the lighting...and the blood! Another game that impressed me visually.
• Gears Of War: When I first played this on a mate's 360 I was amazed at how good a 360 game could look. It compared with any PC game at the time. The levels and characater models are really detailed thanks to the UT3 engine.
• Resident Evil (Gamecube): This remake of the original scares the hell out of me. The graphics are really, really nice for a GC game. The mansion looks amazing really.
• Battlefield 2: The graphics in BF2 are such a huge step up from BF Vietnam released 1 year earlier. The engine looks a little dated now (and BF 2142 didnt look half as good) but damn it's a nice environment to be fighting in!
• S.T.A.L.K.E.R: Everyone thought this game looked a little dated at release but I thought it looked brilliant. The environments look so damn relaistic and the lighting effects are still the best i've ever seen in a game so far.
• Crysis: Well this was an obvious post. The best looking game ever so far. ANd the physics are just so much fun!