I was honestly never one for online shooters. Never. I liked playing over LAN (Lots of time has gone into BF1942 there), but online has just been amazingly boring to me most of the time. Uncharted 2 and MW2 held my attention reasonable enough, but still not really something that stuck with me.
But the BFBC2 demo is kicking ass! It is so incredibly awesome to me! I have no idea if someone finally got the mixture just right for me, but I love playing it. I must have spent more time in that demo than I have in MW2 in total. Which is a bit scary