hmm.. HL2 (demo) runs decently on my PC as well, I could always try that Source stuff out too... time to reinstall Steam anyway.
Uh, basically I'd be able to run (provided I'd buy it) any game that does not REQUIRE a dx9 card... allthough NFS Most Wanted really sucked on this PC, and I'm not gonna buy a game twice (already have it on ps2). Didn't try Carbon, I already have the same game under the name "Underground 2" =P