13. Rainbow Six Siege
Remember when Rainbow Six owned the world alongside Ghost Recon? The latter's Advanced Warfighter was one of the first games on the 360, and the generation-jump was enough to convince any who watched that the new hardware was worth investing in. Six also had some spectacular sequels in the first/third-person hybrid Vegas titles, although following Call of Duty's rise to dominance there's barely been a peep from Ubisoft for either of their flagship shooters, save for Ghost Recon's Future Soldier. With Siege it looks like Ubi are going back to their more serious and contemplative roots, and that can only be a good thing when the military shooter market is comprised of overblown tosh year after year. Picking every shot and making sure every bullet counts is already a breath of fresh air for the genre, and with Siege's big selling point being levels you can completely deform and tear down as you go, Red Faction-style, it's a recipe for success that just needs more exposure to catch on again.