What is a great computer game that includes strategy and sci-fi that isn't complicated and/or expensive?

I'm looking for a great computer game that is simple, fun, and not very expensive.What is a great computer game that includes strategy and sci-fi that isn't complicated and/or expensive?
Try



Sins of a solar empire



Star wars empire at war



Star trek armada



Star trek armada 2



Starcraft



Starcraft 2 (comming out in 2010)



I would look gameplay videos online to see these games first then buy to see if you like them.What is a great computer game that includes strategy and sci-fi that isn't complicated and/or expensive?
Well, everything comes down to what you consider complicated. I'd suggest this game: Light of Altair.



http://www.saintxi.com/



Its a simple strategy game that documents humanity's expansion into the galaxy, but tells a very nice story and has fun gameplay with a) a cheap cost and b) relatively little micromanaging. Check it out!



If you feel that you can handle a full-blown RTS, then yeah, starcraft is going to be a great bet... you can probably get it for very cheap nowadays.



If you want something that is less challenging in a 'non-real-time' sort of way, take a look at the X-COM games (the originals). Fight off an alien invasion with tactical combat. The original is one of the best games I've ever played, and I come back to it every year or so to play through again. Best of all, you can get all five of the 'good' X-com games (2 of the five aren't actually all that great, but... hey, its a bundle) for $5 through Steam.What is a great computer game that includes strategy and sci-fi that isn't complicated and/or expensive?
command and conquer all the way. or fallout 3 GOTY.