The other two I'm playing at the moment are Silent Hunter III, and World of Warcraft (because my girlfriend is addicted... it's the one game we can play together).

I had a similar experience to Doug-Thompson's; I upgraded a few months back to a hot new machine that could suddenly run things sooooo much better than the 4-year old computer that had been limping along with just video card upgrades. With the new box I was able to try a few recent games like Far Cry, that I hadn't been able to run on the old computer. I also got Pacific Fighters, and it was fun flying with butter-smooth frame rates, for once. But that didn't last long. I've settled into a groove now where I'm alternating between SHIII and RTW as my "intellectually challenging/solo" games, and WoW for my "run around killing stuff" social gaming with other people.