I've a list of robot masters I came up with a while ago, with their weapons and weaknesses, but never bothered to post it. Here it is, RM and weapon received first:
Swamp Man -> Mud Tracker
Shell Man -> Clam Sled
Spectre Man -> Homing Spectrum
Satellite Man -> Orbit Beam (Yep, THAT Satellite Man I drew.

)
Dragonfly Man -> Bomber Dragonfly
Brigade Man -> Brigade Barrier
Sledge Man -> Sledge Quake
Zap Man -> Shock Spear
Weakness Cycle:
Dragonfly -> Satellite -> Swamp -> Zap -> Spectre -> Shell -> Sledge -> Brigade -> Dragonfly
Secondary Weaknesses:
Zap -> Dragonfly, Shell -> Satellite, Sledge -> Swamp
I also know how each weapon works, so ask if you're curious.