Savage Worlds, a quite good universal systeme, easy to understand and custom. With miniature rules, Savage World is the ideal rules for high epic saga.
Does BESM need an adaptation for D20 system ? i don't think so. But the level system may be cool to play if wanna run a Gamestation RPG campaign such as Final Fantasy or Xenogears.
One of greatest epic space opera games. A rich back ground with medieval civilisation, space ships, xenomorph and mystical power. A great work for great adventures with a good Dune taste.
A complete game system for free ? The Swiss Army Knife of the RPGamers. Flexible rule and easy to understand. Provide a good revised edition for BESM and SAS. Thanks you GOO.