Ricochet Robot!
It's a puzzle game of sorts, and it's an addictive monster. The object is to try to move a chosen color of robot into his home space by bouncing him off the walls and other robots. There's a web-version here that I play regularly, but it doesn't get truly addictive until you play it with a group.
If you can't find it locally, you can buy it online here. If you buy it online, see if they've got the freebie silver robot in stock. I haven't done any of the silver robot variations, but the price is right.
I'm warning you, though. This is an addictive little monster. Imagine Bejeweled for two players, and you'll get the idea.
