Star Trek RPGs have come and gone over the years, but FASA's system is generally regarded the most highly by Trekkies. This boxed rule set originates from 1983 and is the second edition. It's still highly sought-after.
You are really opening a can of worms if you go here... there are modules, miniatures and more! Truly, a collection in itself, even if you have a main Star Trek games collection.
Loads more Star Trek links appear below the eBay listings.