Hmm... Mecha Pilot girl looking for some action against ugly men or creatures... OH! how about...CthulhuTECH
Its got lots of Mecha and Evengelion type monster/mecha fighting against demons, outer space bugs, and the Esoteric Order of Dagon.
While most of the demons and bugs just want us dead, the EOD has underwater mecha and are *VERY* interested in beautiful girls to kidnap and sire Hybrids and Deep Ones. SOme are slimy octopus type creatures, others are ugly fishmen, but they all obey the slumbering Fish-God, Cthulu himself.
If this intrigues you, I'd be more than happy to start up a game