Depends on what you like. Call of Duty is a run and gun, infantry only, shooter. Battlefield is much more realistic with larger maps in multiplayer, the use of vehicles, and other various things. The story in both games are kinda meh so the multiplayer is the only thing that really matters. For me Call of Duty frustrates me and I much prefer the increased realism of Battlefield. Battlefield is realistic enough to make it so you can pretend you are in a real war for a little while without being so realistic that it overwhelms you.