Just a few ideas, fwtw.....
TORG: The relaunch by Ulisses Speil has been fantastic. Lots of condensing and streamlining the rules without loosing the original game's feel and unique dice/card action system. Lots of data-crunching, though, for the effects of the 100 or so cards in the game (3 different decks, 1 of which determines initiative in combat rounds and other effects; the other 2 decks are action boosts and a deck of cards with narrative effects specific to the Reality the adventure is taking place). Also, the invading Realities have had nice makeovers, fixing some issues and adding in new effects. The Living Land now also includes the possibility of 'Lost Worlds' popping up at random inside the realm. Nippon Tech has been renamed Pan-Pacifica and adds a 'Resident Evil' type virus to the high-tech corporate setting.
7th Sea: 1st Edition; the 2nd Edition has some problems with action and difficulty scaling and scales down Magic. Set it in Vodacce, in the capital of Numa, and you can hit all the main themes: Intrigue, Archaeology, Piracy.
Earthdawn: Solid game system and an interesting setting. Plus, the characters have a purpose beyond basically being murder hobos looking for Help Wanted ads in the local taverns.
Original Superhero Setting: This one is more cultural than a system issue. With Superhero games, almost everyone wants to play the Big Names, so I can understand why OC games like ChampionsMUSH and the old Four Color Comics (to name two) never really caught on, aside from any issues people may have had with staff (if those problems existed, I'm unaware of them)