Traveler is on my list! And I almost played Twilight 2000 way back in '91, but the GM was a gun nut. We took 2+ hours to make PCs, of which 1.5 hours was him discussing firearm options. I finally got bored and left when it became clear we weren't actually going to play.
Similarly, I'd love to play Champions but have never had the chance. I almost did once, but my totally power-gamed hero Meter Maid (she turned bad guys into parking meters until someone put in a quarter) was justifiably rejected by the GM, and the game never actually happened. I was sad.
I would also love to play a game of Spawn of Fashan, but I'm pretty sure it's impossible to do.