Games You've Never Played – But Wish You Had

I regularly hear it boasted that there are now more roleplaying games available than at any time in the hobby's history. That's almost certainly true, though it's a very odd boasted, given that I don't think most gamers ever get the chance to play more than a small number of them (or, if they do, they can't possibly play them for very long). Mind you, this was true even back in the first decade of the hobby and I can distinctly recall seeing or hearing about many RPGs I never had the chance to play myself.

This got me to thinking: what is the one roleplaying game that I've never played but wish I had? I thought about this question for a while and considered several possible answers before settling on an answer that satisfies me: Space Opera. Though I am a devoted fan of science fiction roleplaying games (and even wrote one myself), I've never played FGU's 1980 entry into the genre. I own a lot of the game's releases and have read several of them avidly, but, more than four decades later, I've never never succeeded in playing the game, though I did come close a few years ago.

I suspect the main reason I never played Space Opera back in the day is that I already owned Traveller, Star Frontiers, and Star Trek. Between them, I had more than enough options to sate my appetite for sci-fi. More to the point, aside from a couple of guys I met a public library games day, I didn't know anyone who played Space Opera regularly, which made it less likely I'd ever do so. But I always wanted to play the game, in large part because it was such a delightful mishmash of elements ripped bleeding from the bodies of popular science fiction books, tv shows, and movies that I suspect it would have been a blast to play. Honestly, I still think that, even if I remain somewhat skeptical of its rules.

What about you? What one roleplaying game have you never played but wish you had? Non-existent bonus point if you explain why you've never played it and/or why you wish it were otherwise?