I was exactly the same and now I can use the controller decently now, could still be better but I will get there. I still play PC FPS games but most the time I will go on the 360 so I can play with friends. Once upon a time everyone was PC gaming, over the last 5 years I would say more friends have gone back to the consoles instead of constantly throwing money at decent hardware to run the games in their full details.
Although I have L4D1 on both the PC as I got it when it was first released then got a cheap copy for the 360, L4D2 is a poor version on the consoles and there is a lot cut back and dumb'd down so I went with the PC version for L4D2 and will probably get a 360 version when I find it on ebay for ~£15.
As for MW2 I am spending most my time on the 360 version purely due to the number of friends plying it and then the odd game here and there on the PC version.