It's Savage Worlds for me as well. I've played a number of genres and it handled them all well. The other factor for me is the Pinnacle staff who are always helpful and friendly.
They keep a tight reign on their forums as well so there is very little trolling. Clint Black is their core rules...
I love the Mythos but don't care much for CoC. I'll cast another vote for Realms of Cthulhu. We did a review over at The Savage Troll that discusses the various styles of play.
RPGMapShare.com | Your source for gaming maps and mapping objects is a great site as well. There are also artpacks you can download while inside MapTool. Also check out the User Creations section of the RPTools.net forums.
I have a few articles on mapping at rptroll.blogspot.com. Look for the...
I recommend going to the "looking for group" forum area at rptools.net (home of MapTool) and posting there.
RPTools.net • View forum - Looking For Group
Sounds like a great campaign. I have the Firefly RPG and it is very Savage-like. I've considered Savaging the universe myself. <sigh> So many games so little time.