Well,
There's 7 Deadly Sins, though it requires a signup as a beta tester and participation in some sort of live sync thing that allows DANMAN3712 (the creator of 7DS) to change files and have the changes show up on the tester's comps live.
There's dolynick's StarGate races mod, which adds the following StarGate races: Wraith, Ancients, and Asgard.
There's Sins of a Galactic Empire, a total-conversion mod of Star Wars (you might have to run it through harpo99999's mod updater tool).
There's Star Wars Requiem, which adds the Empire and Rebel Alliance to regular Sins (the SW races are balanced against the standard ones).
Then there's a Stargate total conversion in the works, ManSh00ter's The Last Stand mod which is also in development (though he's said that "soon" will be a release), the Dawn of Victory TC mod (a "when it's done" mod), and a few others I think.
Oh, and EvilTesla-RG's Tri-Pirate mod.