I meant to post this one on Friday, for some Friday happy fun-time. I guess Monday can be a fun day too though.
This game is one of the most addictive games I've ever played. At least as far as cheap online games go. I haven't played it in a while and I think they're up to a version 1.5 now. It's called Desktop Tower Defense, and you get to set up various defense towers that kill creeps before they make it to the end of the screen. It's weird a first, but play it a few times and you'll be hooked. If you're easily addicted to mind games (like me), you might want to wait till Friday, or whenever you really have nothing left to do for an entire afternoon.
Desktop Tower Defense
If you're still bored (which would be amazing), here are a few more of my favorite online games.