"He has electricman, gutsman and protoman's abilities."
Oh Okay. Well in that case Megaman would take out Space Ghost but it would be hard since Space Ghost has the advantage of flight and Megaman doesnt... Megaman will have to blast Space Ghost wiith the Electric Man currents and hope he can catch him. Cause it aint easy catching someone who can fly and turn invisible and you cant fly..
If we're talking about old school Space Ghost, then Space Ghost. Yeah. He has a beam/ray for pretty much everything. Plus he could fly at FTL and has that inviso-thing of his to make himself invisible/intangible. SG ftw.