The arcade classics are coming back in force, and one of the big daddies of them all is certainly the Metal Slug series. Metal Slug 1, 2, and X were fantastic, but Metal Slug 3, in my opinion, stands apart as simply the best run-and-gun game of all time. Not only is it beautiful, but the branching paths, extra weapons, and co-op multiplayer will keep you entertained for years.
You can get it on Xbox Live Arcade for 800 points, but beware, this game is so hard that it will actually play you. My advice is to get a sweet arcade stick, although I’ve been playing it on my keyboard for the last few years. Now where’s my Radiant Silvergun?!