The Raid. It was AWESOME, and far more brutal than I was expecting. The characters aren't exactly oozing with depth and development, but I didn't really give too many fucks. You don't watch a movie like this for well written drama.
Also, I know everyone has said this before, but The Raid and Dredd really are very, very similar. They're eerily similar in parts, beyond having the same basic premise of "cops get trapped in a tower block full of bad guys" - more so in the earlier parts of the movie than later on. Weird thnig is though it doesn't seem likely anyone copied anybody else; although The Raid was released before Dredd, Dredd was in production before The Raid. And both were independant movies made at opposite sides of the planet from eachother. It seems like it's just a very bizzare coincidence.
Having said that, they are different enough that you need both movies in your life.