Make sure after taking your controller apart to either:
A) lightly sand the plastic
B) prime the plastic with a special plastic primer
or
C) do both.
Assuming you're using spray paint, some are made specifically for plastic (Krylon & Rustolium make a number of plastic paint) and others are multi-surface. With a plastic paint there's no need to prime, but I'd still give the controller a very light sanding just to remove any imperfections and help form a better bond. With multi-surface or automotive paint you will need to sand and/or prime. Failure to do so will result in peeling & chipping and poor color representation.
As with all sprays, apply very light coats. The number one mistake most people make is to go spray-happy and try to get the object covered in one or two coats. By doing this your paint won't dry properly and you'll be left with runs. Just spray a very light coat, wait an hour and repeat. Using four or five light coats will give you a much nicer finish.