If you haven't heard of it, GGG...
...No, not that GGG...
Giant Guardian Generation is basically Super Robot Wars: The Tabletop RPG. It's a cool, free system, you can pretty much recreate any pilot and any mecha with a little imagination. (If I ever find the notebook I wrote the stats in, I'll post my stat blocks for Lelouch and the Shinkirou.)
The PDFs are here: http://tk31.blogspot.com/p/downloads.html