Lots and lots of them, I chronicled many of my paint experiments in the gunpla thread starting here. Almost every piece has several layers of paints in addition to the primer.
Solvent based
Rattlecans:
Mr Surfacer 1500 black
Tamiya TS-14 Gloss Black
Airbrushed:
Splash Paints chameleon
w/ Mr. Leveling Thinner or Mr. Rapid Thinner:
Tamiya X/F acrylics
Mr. Metal Color
Mr. Metal Color GX
Water based
(All airbrushed)
w/ windshield wiper fluid as thinner:
DecoArt acrylic craft metallics
Liquitex Basics acrylics
Sennelier Abstract acrylics
w/ Vallejo thinner:
Vallejo Model Color
Vallejo airbrush primer, grey
Top coated with Mr. Hobby Premium Top Coat gloss