Which Underdog Movie Will Be The Summer's Biggest Sleeper Hit?S

A lot of underdog movies are coming out this summer (and some of them will be just plain dogs.) Which of these scrappy up-and-comers will tear out your wallet with its bloody celluloid teeth?

Note: As with last year's similar poll, we're not including movies that are expected to be hits, like Star Trek or Terminator. If you want to make a case in the comments as to why you'd be surprised if Star Trek makes tons of money, go ahead. I was debating whether to include Wolverine, but a lot of people seem somewhat pessimistic about its chances now.

Have you never heard of some of these movies? More information about Pandorum is here. More info on District 9 is here. More about Moon is here. And here's Game.