Depends, DOA4 is sure to offer the better multiplayer, as COD2's sucked hard. Where as fighting games are never really fun when played alone. Plus you have to ask yourself this: Do you want yet ANOTHER FPS (when you already own one) or would you rather have something (kinda) new (okay so it's just a rehash of DOA 3/U, it's new on 360). Also take into mind the cheap ass factor: COD2 has been out for almost a month now, surely you can find a used copy either online or at a B&M store, or maybe even a sale, where DOA4 has all of one sucky sale online.