I agree with cosian about Distant Worlds. One of the things I like about it is the options for galaxy set up. I've played various scenarios including a few "barbarian at the gates" where I had one large galaxy spanning empire and a lot of smaller empire. I've done variations of it with havign the large empire be very low tech and the smmallers one having a higher starting techlevel and vice versa. I've done traditional 4x starts where everyone starts off the same.I recently did a human pre-warp start while all my opponenst started with level 2-3 techs.
You can even customize how many independant planets you'll find or the number of habitable planets. I've set these to very low before. Each faction had to rely on 1-2 shipyards and more mining stations for resources. The amount of customization can be almost daunting when you first look at it, and the game does have a bit of a learning curve. But with the AI able to manage entire portions of the game (research, ship design, etc.) for you its not too bad.
The game isn't perfect. The AI will occasionally do stupid thigns when you have it controlling things. And pre-shadows (the new expansion) the game did have some issues with money bloat in the mid to late game. But all these are very minor issues IMO.
With the release of the new expansion Distant Worlds and all the expansions are on sale for $20 USD each until July.
