ive seen a lot of snap kills in FPS games I play. people tell me this is because of sticky aim due to using a controller instead of a mouse pad. I just bought a x box 360 controller and tested it on Titanfall. but didn't notice any sticky aim when I tested it in the games tutorial.

do I need a special controller or, is it a game by game function.

I'm guessing it's a game-by-game basis.

I have played a few games where you can toggle an aimbot on and off. Some even have it built into the easier difficulties.

Game-by-game

It is purely a game-by-game function and can be toggled in the settings, if the game supports it.