I'm always surprised by how well older PC games hold up, visually.
Compare that to console games.. where you honestly can't even believe you were able to make out the screen! Ever fire up an old PSX? Looks like smeared goop! I felt like I went blind.
Honestly, just about any PC game running in your highest resolution, with full blown AA and AF looks good enough to me. I've never run into an older game that looked too antiquated or anything.