I found
Galaxy of Fear. (It was a Star Wars-set, forums-based RPG, apparently defunct now.) Ryme's sense of humor strikes again!
I suspect the "Restaurant at the End of Las Vegas" is an inside joke that we just don't get. So far I've found:
A play-by-email Twilight Imperium game that the GM named "Restaurant at the End of the Universe." It uses a wiki to help track and explain the game. (Where's the Vegas reference?)
A forum-based "Avengers" setup that has the words "end, Restaurant, and Las Vegas" in a post in one of the threads.
"Rainbow Six: Vegas" (new Italian restaurant add-on). Go figure.
A Shadowrun guide to Las Vegas.
Someone else can figure out this one!