For color I like an Iwata LPH-400

For clear I like an Iwata W-400 ( meant for waterborne color but it is an awesome clear gun)

Also I have played around with 3M's plastic gun, the accuspray- really, really good gun for the money and you can change fluid tips at the drop of a hat. Sprays like a new gun everytime with very little cleanup.

Any gun can work but these work well for me.