I like BF2 more than CS.
To be fair, I haven't played CS:S but BF2 is more "random" and more stuff can happen. Plus, I am better at it. I remember playing beta CS 1.0 when it first came out. We used to have little 6 player LANs and play UT. "Hey guys, lets play this new mod!" We did nothing else for about 2 years. It was 'effing great fun. However, online I suck hard. I can usually out think most people, and I know what is going on, but I can't shoot for crap.
Usual CS game for me...
"Ok, he went this way last time and I am sure he'll think i'll do this, so I can flank him and shoot him in the back! haha!"
* Man runs right into my trap
* Fire 5 times, hit 1-2 times
* Man turns and headshots me
Battlefield I can survive at. Plus, because the battles are less small fights and more large battles individual skills is negated by tactics. Again I out think most people, but this time I am in a tank.