I would say BF3 all the way because BF1942 started me in the FPS years ago however the fact that DICE refuses to allow people to mod BF3 is odd because usually EA would be the one to f**k up something so good.
...What?
They're planning to release modification tools for modding communities that have legal rights to do so in 2012-13.
Having it only released to companies will prevent the creation of hacking tools and modifications to prevent cheating in the game, and only allow the creation of modifications that other users can enjoy.