I main the L-3 Nozzlenose (see sig) and substitute it for the Luna Blaster, Custom Splattershot Jr. and the Splash-O-Matic sometimes. I love disruptors, and L-3 is really fun for me, it's range is so good for zoning, and it's pretty strong if you've got good aim. I play the custom when I'm feeling sneaky - since it really demands stealthy play, but I use it on Ranked only sometimes, usually on Turf Wars, and switch to the Splash-O-Matic when I want to play a more aggressive role. Luna Blaster and L-3 are my Ranked choices, though I use the Nozzlenose more.
Luna Blaster seems pretty popular but I love it's space theme XD - While the Nozzlenose looks neat because it resembles a revolver.