Hmm... A lot of games starting to look good recently... I'd wager that my Half-Life 2 looks and plays decently on my system. It works with all the settings cranked up to highest except anti-aliasing and only goes slow at the start of each level, otherwise it's great.
I recently got Call of Duty 2 as well and while its graphics aren't mind-blowing, they're great till now. I really like the Egypt levels - that is good graphic and level design.
Like Rogue, I wish I had Oblivion, but it will murder my system.