I recently played some Resistance: FOM and was astonished at how huge the difference is between older games and newer ones.
For comparison here's some screenshots from the best looking games each year for both the 360 and PS3.
2005:
2006:
2007:
2008:
2009:
2010:
So far in 2011:
As you can see each year has had huge improvements over the last! And we are not even finished yet! Games like UC3, ME3, Battlefield 3 and Skyrim are all shaping up to be absolutely gorgeous games.
Feel free to post any pictures of games you want.