What are some good pc games that have to do with war and space combined?

k, im lookin for a game that is like spore, but not as cartoonish, and more realistic. but something to where you can create your own ships, and fly through space, like EVE. also something like spore where you can visit the surface of the planet, build large cities, and actually be able to leave your ship, like halo. and also be able to invade planets, send troops to the ground, destroy cities and all that good stuff. are there any games like this?