Ascend: Hand of Kul is a free-to-play RPG on Xbox 360, and it's surprisingly fun. Sure, you do have to look past all the HEY BUY THIS but it's a decent hack-and-slash where you can peek into other players' worlds and banish some of your enemies for them to deal with. Not a bad gimmick.
There are definitely some problems with the game HEY BUY THIS but overall, I managed to enjoy myself for a few hours without spending any money at all. The Dark alignment ended up feeling incredibly slow to me, but that's supposedly the tradeoff for high damage. I still need to try out the Light side for a good comparison.
Ascend is out now on Xbox Live Marketplace and you can download it for zero dollars.