Don't forget the least supported TSR rpg of all time: Metamorphosis Alpha. Also, didn't TSR produce the first edition of the Empire of the Petal Throne rpg? TSR was banging 'em out in the 70's and early 80's.
I never heard of these games. What were they about?
These are both excellent games, if you like a blend of fantasy and science fiction.
METAMORPHOSIS ALPHA - MA was the first scifi-based RPG that I ever played, mixing ray guns with mutants with swords. Lots of fun and old-school character death. Characters live on a giant world-sized generation ship to the stars, but something bad happened and the ship has lost its way. Some characters and animals have mutated into new things, and some common things have become very deadly. Each level is a world, so there are lots of opportunities to have variation. MA was first done in 1976, later was released as part of TSR's "Amazing Engine" game line, 3E was a 25th Anniversary edition re-done by James (Gamma World) Ward, 4E was a huge expansion of 3E, and a new 5E is being planned based on D&D4E. The 1976 MA rulebook was a stand-alone book of around 48 pages.
EMPIRE OF THE PETAL THRONE - This was released in 1975 with rules which were very similar to D&D. It's basically a fantasy world, but there are hints of a "lost civilization" theme behind the scenes and it combines fantasy with scifi. EPT was designed by a professor of linguistics (much like Tolkien) and the world is rich in history and ambaince. I find that there is almost too much strangeness for my likiing, but many players are fanatic about the world. This has seen several reprints and was totally revised by Guardians of Order before the collapse. There are several novels written by the EPT author (M.A.R. Barker) and a lot of information about the language, etc. The 1975 EPT was a boxed set, with rulebook and a couple of maps.
Both games got decent support in Dragon magazine, back in the day. If you have questions about either, I'll be happy to give more details.