I'd recommend BC2 + BC2 Vietnam over BF3 any day. BF3's extremely groggy in-game, not to mention having to deal with Origin and the web browser is a complete pain in the ass. The only thing it has on BC2 are jets, so unless that's a selling point for you I'd recommend the predecessor over it completely.
And besides, in BC2 you can still fly helicopters. Or in my case, fly helicopters backwards and crash them into the ground.
Anyway, for people wondering if BC2 is any good or not, just a reminder not to mix up BF2 with BC2. BF2 has old graphics.