Multiplayer wise, since it's pointless to compare anything else.
MAG - huge, engrossing, tactical, team-based, addictive, smart + well designed
MW2 - small, arcade, rambo-wannabe, dumb + not so well designed
Bit biased? Yes. But the fact is that I can't look back at MW2 multiplayer after playing MAG as a platoon leader, from a great clan on a great faction. MAG has depth MW2 lacks.
MY HYPE LIST: 1) Gran Turismo 5; 2) Civilization V; 3) Starcraft II; 4) The Last Guardian; 5) Metal Gear Solid: Rising