Back in 1981 while I was attending college I happened to stumble across this jewel of a game. The local wargaming club had just discovered it and was running original scenarios for it in addition to those of Traveller, which had been around for just a few years.
Space Opera has a unique character-generation system which I've found to be more satisfying than the current crop of "generic" RPG's. It's not a trivial task to create a character (done randomly using the time-honored tradition of rolling dice), but ultimately the player ends up with a true science-fiction player character, with skills and abilities specific to the far-future universe described in the rules and fine-tuned by the Game Master.
Combat requires just a couple of dice rolls to resolve hits and damage, although the Game Master has to keep track of variables such as range, speed, armor and size. The weapons table lists other variables (armor penetration, reliability, range, lethality) for each of the weapons listed -- and there are a lot of weapons, ranging from the dagger to the good ol' blaster rifle.
Perhaps the only drawback to this game is the black-and-white graphics, sprinkled sparingly throughout both rule books. Anyone used to the current multi-color, glossy-paged hard back RPG's may be disappointed with the artwork in Space Opera. But Space Opera is a game for the mind, and hard-core science fiction RPGers could do a lot worse than to choose this product.