If you have not purchased the original version, you're in luck because you can now get all of the spectacular add-ons for the same price as the original game.  One of the best computer games I have ever played.  If you  like Warcraft or Age of Empires, you'll love Starcraft.  The aspect that  surprised me the most in this game were the scenario and video segments in  between levels.  Some of the best computer animated film I've ever seen.  Definitely worth the price considering how long the game remains fun,  original and challenging.