Mirror's Edge still has my favorite visuals of any game ever. They're not the most high fidelity, but they're definitely not the least either, and everything is so beautifully stylized. The way the colors mix with the all white environment and the blue sky is just fantastic throughout, and the game varies the environments nicely, as it's not the same exact color patter through the entire game.
It's also one of the few games I've noticed that pulls of relatively low-res textures while looking close to lifelike.
Dunno, I just think it's beautiful. The comic book cutscenes were hit and miss for me, but the world and visuals were just so striking at the time. IMO, Mirror's Edge still looks better than any game DICE has done since then, even BF3. It came before their sunray and dust phase, though, so I suppose that helps.