Here's one for the 360 owners - if you've got a GOLD Xbox Live account, you can sign up for the beta of Red Faction: Guerilla.
The beta is being run by fileplanet, but you don't need to download anything from them. Sign in with a gamespy/ign account (can be a free one, you don't need to be a subscriber any more) and you'll get a key. Simply go to "redeem code" on your 360, enter the key and you can download it right away.
Just had a blast earlier, it's quite fun!