How have I gone this long and missed this thread?
Don't know if this has been mentioned yet, but even if it has is deserves being mentioned again
IMO
Planetes aka PlanetES
http://en.wikipedia.org/wiki/Planetes
If you're after big space battles, this isn't it, however it is exellent sci-fi about rubbish collectors in space.
Ok that sounds bad but it's not, there's some good underlying world & corperate politics in the story and the whole thing is well thought out.
And the artwork and animation is very good too.
Another intresting one is Flag
http://en.wikipedia.org/wiki/Flag_anime
It's a realy nice blend of cgi and traditional animation, it's a civil war story set in a made up euroasian country
But it's all told through the point of view of war corrispondants.
Again sounds odd but is very good.
EDIT: Big robots and gunfire, check out Gundam 0080 think that'smy favourate of the gundam stuff I've seen
EDIT: opps getting mixed up, 0080 is good but the one I ment was The 8th MS team