After beating everything there is too beat in this game, here's my opinion.
The good:
-Awesome environments
-epic characters
-insane gun list
-fantastic multiplayer
-dedicated servers
-good story
-frostbite engine (fully destructible environments)
-relatively camper free
the bad:
-short campaign
-8 maps by default (fixed with DLC)
-4 game modes, which doesn't really both me, but it's not as versatile as Modern Warfare 2 or one of the Halo games.
- bad graphics on some gun iron sights (especially the default assault rifle, the AEK). It can be fixed with a red dot sight, but it is slightly annoying.
The story is amazing, and frequently pokes fun of Modern Warfare 2 (example: "No! If we tell [the lead general], he'll send in some Special Ops douche-bags with heartbeat monitors on their guns! The single player story is short but very, very good.
If you're thinking about buying this or Modern Warfare 2, go with Battlefield.