Multiplayer really defines most genres these days and is usually what keeps people coming back to games. A good multiplayer game usually consists of leaderboards, stat tracking, a reward system, and lots of maps, customization options, and just super fun addictive gameplay.

Call of Duty: Black Ops

Modern Warfare redefined the FPS multiplayer scene and Black Ops perfects it with Wager matches, tons of customization options, perks, ranks, and well-made maps. Nothing can really hold a light to Black Ops, and to me is probably one of the best FPS multiplayer games of the decade.

Runner-Ups

StarCraft II: Wings of Liberty

Halo: Reach

Battlefield: Bad Company 2

Rock Band 3