Ranked in these QuestionsQuestion Ranking
Pros
Pro Free download
Pro No fixed setting
The Tri-Stat system has been used in multiple genres, including Silver-Age Sentinels (superheroes), Ex Machina (cyberpunk), Dreaming Cities (urban fantasy), Tekumel (fantasy), and BESM (anime--multi-genre by itself).
Pro Rules-moderate
Not so rules-light that you don't know how to play, and not so rules heavy that you get bogged down studying books.
Cons
Con Out of print
Guardians of Order, the original publisher, is defunct. White Wolf acquired the rights, but hasn't continued support. There were many rulebooks created using this system, but don't expect any more.