Mostly King's Bounty: The Legend, which is surprisingly good in a HOMM-ish sort of way, but I'm taking a couple days off after having played it too much and it getting a little grindy at the end clearing maps to build up enough for the final couple areas.
The other one I'm actually spending a decent amount of time with, or at least playing regularly, is AI War, which I play weekly with a group of people I know, and which is also surprisingly good. The obscenely large fights (thousands of ships at once all flying around and blowing stuff up) and ridiculous strategies we plot out (and sometimes even pull off successfully) are a good time.
Everything else is mostly on and off, like a bit of Burnout Paradise just to goof off and occasionally unlock things I haven't done yet, but I'm mostly finished with it. Also occasionally I'll do one of the stand-alone adventures in The Witcher, even though I finished the main game a while ago. Same with Duels of the Planeswalkers every now and then, but I've mostly given up on it until they fix some of the game-breaking bugs that make it lock up in multiplayer games half the time (How dare you right-click on a card? What were you thinking?).
For some reason I've really wanted to play Titan Quest in the past couple days, but every time I tried, I got bored really quickly doing the same thing again...until I tried the xMAX mod that spawns basically the largest number of enemies the game is capable of handling at once even if you're playing by yourself instead of multiplayer, and it changes the way it plays enough to make it interesting again, but we'll see how long that lasts.
I have several that I haven't even started yet, though, so not usually much replaying of stuff I'm already done with or bothering to 100% games if I've done everything I want to already, so those'll mostly drop off the list quickly.