I've sunk about the same amount of time into each game about 20 days haha and got decent at them both and the only one I would run back to save if it was in a fire (If they were disks obviously haha) is Modern Warfare theres something about that game that sparked my love for FPS, I used to all RTS only but God I love Call of Duty sure it isn't always based on skill but if you are really good at it you can shit on another team easily. TF2 would be better to be compared to say BF seeing as its team based but It is a great game and I loved it aswell.