BFBC2 is my suggestion as well. CoD BO is very fun too, but gets very frustrating since it is to quickly over with IMO. BFBC2 you will be playing for quite a while. Much more difficult. The only gripe I have with it, is that it takes forever to kill enemy players. Unloading the majority of your magazine to kill them, as opposed to CoD HC mode where they die by the 2nd shot to the chest (MUCH more realistic). They both have their pros and cons. If you like large scale FPS with long games (30 mins is a typical fast game) then BFBC2. If you like quick 10 min games tops, then pick up a copy of CoD. I haven't played CoD4 or MW2 on the PC, only Black Ops. So I can't really say too much about them, but I like throwing in Black Ops when I want a quick FPS fix before I go to the gym/school/work. Ranking up in BFBC2 is also much more difficult. XP doesn't come as quickly as the CoD series. I play it casually (game or two every couple days) and I am only SGT silver (lvl 11 I think?) but you can get unlocks fairly fast. Was maxed with sniper by lvl 6 I believe if I remember correctly. As opposed to people going prestige by day 2 of release with Black Ops. Team work is also a bigger necessity I've noticed. But not as much as it was with BF2142 IMO, which is my favorite BF, sadly not many people play it anymore. Tried logging onto the servers about a year ago and only found a few.