Tallima: I had a lot more fun with BFBC2, like some above posters. I enjoy BF3, too. But there's something about BFBC2 that's just more fun overall.
That said, once you play BF3, it's hard to go back to BFBC2 b/c it does have a lot of features that were missing. Jets and aiming are good and all, but the level design is so much better. They incorporate a lot of choke points in the maps, so you get a better feeling of taking and losing your position.
The rent-a-servers does suck. And I think it may be because of EA's bad losses that the rent-a-server system is up. If you have kids around, you can't play anymore on the off chance of a nudie pic showing up as a server banner. And you'll get back into stupid rules, clan-only or other annoying situations because of it.
Is it still a great game? It is. And EA says they'll keep the servers up through 2013, so that's another year and a half of play. BF4 comes out in 2014.
I got BF3 as a gift, but I might have lifted my EA purchase ban for BF3. It's a good game.
DICE/EA said they are gonna support BF3 even after 4 is out because hey they did the same thing to 2