Ummm....I assume that is a typo? 2400 and a 750ti correct?
BF4 will get an average of 36fps at 1080p ultra, so I'd probably do medium settings.
Gmod - will be no problem, high settings 60fps I'm sure.
Dayz standalone is horribly optimized, nothing runs it good, don't know what to tell you there. The mod is more cpu intensive, you should be fine at medium-high settings.
Simcity - don't know, will probably be fine as it's not a demanding game.
Ghosts - Theoretically medium-high, but it is not a good pc port and has issues, do research on it.
Crysis 3...Probably medium. Very demanding game, one benchmark claims 42fps average for the 750ti at high, so I would probably do medium.
Team Fortress 2 - another source game like Gmod, will run at high settings no problem with 60fps.
All results assume 1080p resolution. Also, I assume you have a somewhat decent power supply? You don't need an amazing one for the 750ti due to it being Maxwell, but still...