Iczer is a fairly cool and mostly serious series of anime. It consists of "Fight!! Iczer-One", "Iczer3"
and "Iczelion". Iczer-3 follows Iczer-1, but Iczelion takes place in an alternate universe.
Iczer-1 is a sci-fi revolving around an alien invasion with a single rebel who trys to save the Earth with the help of the requisite schoolgirl.
Iczer-3 follows up Iczer-1, with a younger sister of Iczer-1 having to help out against the evil alien force while Iczer-1 recovers from battle.
Iczelion throws Iczer out the window with the exception of keeping the character Nagisa (the schoolgirl from Iczer-1) who is chosen to become an Iczelion. A warrior race that fought for good was dying, and made robots that when they joined with humans gave humans the abilities of their species so that humans could protect themselves. Of course this led to the also-standard nude-putting-on-battle-armor scene.
All of these anime had great music, and I'd recommend collecting the soundtracks if you get the chance.
Some nudity does occur in these videos, but it's not the crux of the video. For the most part this is human/alien vs other aliens, with a few mecha thrown in. And the reason there's no Iczer-2 movie is because Iczer-1 through Iczer-3 are characters on this series, with Iczer-1 being the main hero of Iczer-1, and Iczer-3 of Iczer-3. Iczer-2 was an enemy of Iczer-1's.
And if you end up with an Iczer CD you don't want, let me know, I'll gladly take it off your hands!