And if anyone was a fan of the Master of Orion series (as they should be), it's getting a new game: http://www.gog.com/game/master_of_orion
On the other hand, I recently started playing MOO2 again and it's just as fantastic as ever. Brilliantly balanced, quick to play, lots of different strategies, etc. I haven't found a 4X game since that really quite got all of the things right.
(Get a recent fan patch for MoO1, if you play it.)