There are a crapload of games I own but have never played. Strangely enough, back in my high school and college years, pretty much every game I bought was played at least once, even if I didn't really understand the system completely.
The Pacesetter line was played, the Fantasy Games Unlimited line was played, Runequest, Traveller, MERP, Rolemaster, Spacemaster, GURPS, Rifts... on and on the list goes.
I think we even ran a session or two of Deadlands (1st Edition), which went over about as well as Boot Hill - everyone had the Star Trek episode with the Tombstone shootout in their heads I think. Not a good scenario for a western.
All this leads me to Savage Worlds. Apparently a system loved by many, with a decent number of assorted genre sourcebooks and adventure paths, I just have never been able to wrap my head around it and it's "dice size" for stats concept. I want to. The SW Explorer Rules Digest has been in the backseat of my car for years, handy when you have time to kill and need something to read. Still, I'm left scratching my head.
I can never seem to figure out just how the powers / spells system works, probably because this game isnt well suited for fantasy and that is where I am fairly rooted. More likely, I'll need to actually play in a session or two before it really "clicks".
Then again, there is just so much other stuff out there that is also good, why should I keep at trying to grock a system that I'll probably never play anyway. Good thing everything I own for Savage Worlds, with the exception of the core rules, is in PDF. Not much to pack away ;)