I'm currently designing a game that will be running in browser(regular text based mostly) but I'm falling short on great ideas. Currently, the player is the manager of different game units, such as spaceships, stations, buildings. The game revolves around building and spreading out throughout the galaxy, mostly "base-building" and war.

Since people here know a lot about games, though it's the best place to ask for games that have similar mechanics to get some great ideas.

What you asking for is vague .Basicaly you want to know RTS or tund-based strategy game in space. That's it?

A few example :

Galactic civilization
Star wars empire at war
Sin of a solar empire
Alpha centaury.
Eve online (not really RTS, but it's in space, and it's great)

Also older titles like Master of Orion series and Imperium Galactica might help, but I regard Galactic Civilizations (suggested by Navezof) as one of the best in 4X space games.

Since it's for the web you should have community/social components. Just as basic as a chat would do. Back-end heavy games also opens up for monetization, if that interests you. Older games usually don't involve these kind of features so look at contemporary farming games or the browser-based MMOs for ideas. Clean them from their form-factor and make use of it. I've never heard of space pigs...

Thank you all for great feedback. Despite vague description of my needs(sorry about that), you managed to suggest me very good titles! Now I just need to obtain the older titles somehow.

"What you asking for is vague .Basicaly you want to know RTS or tund-based strategy game in space. That's it?"

Both. The game will be neither, but I'm looking for interesting gameplay elements from both.

If you intend to go this way, then try the "Total war series" (the most recent being Rome 2 : Total war)

They have a really good mix between war-game and RTS battle phase. So if you want to do both, I think it's a good reference.