#19: Rock Band
Why It's Great: Picking between the PS3 and 360 versions of Rock Band is pretty much a toss-up. The 360 has a better online structure, with DLC available days (and sometimes weeks) earlier, as well as a larger pool of opponents to battle against, but those benefits are dwarfed by the PS3's packed-in wireless guitar. You may be able to buy wireless guitars for the 360, but the wired one that came with the game will always haunt you. So do yourself a favor and pick up the PS3 version to avoid all that.
