Dark Messiah: Might And Magic. It looks like a crappy RPG Game, but it has the Source Engine so AWESOME PHYSICS TIME! And the game abuses that to no end. Every combat is set up specifically so you can kill your opponents in hilarious ways. Throw barrels at them, throw rocks at their heads, throw oil and set them on fire, kick them into fires, kick them off cliffs, kick them into each other, kick them into spikes, kick them off balconies and watch them dash their brains out on the ground. As you can tell, the kick button is GOD.
I seriously have not had so much fun in combat in a long time.
Re-Volt. It's old but I still love it. It's a little racing car game but with remote controlled cars and pickups. You race around shopping centres, toy stores and museums etc but it's just so addictive. I think it might be abandonware now (I don't know) but I know you can download a full working copy for Windows Vista and 7 off the iternet for free.
The King Kong Game of the Movie. I've mentioned it before. Nothing beats throwing a flaming spear through a dinosaur's head or a giant centipede and watching it ragdoll while it's pinned to a wall.
Heroes of Might and Magic V. Yep, the original series of the spin-off RPG up there. It's completely different but I still love it. It's more of a turn-based strategy RPG. There are a lot of problems with translations and subtitles in the English version and the cutscenes (especially of the first expansion) are EXTREMELY cheesey, but hey, the gameplay is awesome so I forgive it.