Duracoat is the current rage.
http://www.lauerweaponry.com/
Many colors, very durable, offers camo kits. Reasonable price.
Plus, they drive the anti's crazy because they claim that people will paint real guns to look like toys and then all the kids will run around shooting each other. (Michael Bloomberg, the NY mayor actually had a press conference about that topic comparing a real gun painted red to a toy gun that had a sealed barrel and no trigger and claimed no one could tell the difference.)