I don't normally pimp my company's products here, but it really is a good game - Metacritic has it at 91% over 16 reviews, including several Editors' Choices (the "Gold Edition" contains both the Dark Avatar expansion and the previous version).
If you're a strategy player, you owe it to yourself to try this game. Even if you don't think of yourself that way, I'd ask you to give it a go - you may find you like it just for the cool ships you can make. There's some hints on playing the game at the GalCiv Wiki, and more help available on the forums.
If you know me, you know I wouldn't waste my time working at a company that didn't stand by its products. Stardock regularly updates its games, so if you do buy it, you can be sure of getting your money's worth. And we don't do Starforce. :-)