Wow! Did not expect so many more answers / suggestions whilst I slept. May take me a while to get into gear and check them all out - but thanks in the meantime folks!
That looks pretty damned awesome!

Salvation prophecy is really good. It is more about combat and some exploring than trading tho. It is a lot easier to get into than the X series I didnt even read the manual and it was not a problem. I bought it on Desura. The game should be on GOG too, its DRM free.

+1 for Precursors. It's a fun game, though very unpolished.

AI War is a great RTS, though it's not available on GOG due to having a minor bit of DRM. Luckily, it's not very intrusive, and the game's pretty cheap, and you can try a demo of it (and any of its expansions) by just downloading the game and not entering a serial key.

http://www.arcengames.com/w/index.php/aiwar-features

you might want to check out Predestination It's a 4x strategy game that's coming out next year

Just thought I'd ask and see, but if anyone picks up the "Santa in Space" bundle today and has a spare key for Nexus: The Jupiter Incident or Haegmonia Gold I'd certainly appreciate it (two of the games I found thanks to you lot!) as I dont have cash right now.

Also, I've a giveaway on for a few spare keys of my own (steam only sadly), so you might want to jump in there as I'll be closing it at 4am GMT.

http://www.gog.com/forum/general/a_bundle_of_bundled_stars_giveaway_ending_201212

Bit surprised no one mentioned Evochron Mercenary yet, its basically Elite 4, has quite good graphics and features physics and seamless planetary landings.

http://www.starwraith.com/evochronmercenary/screenshots.htm

The 90 minute demo is the full game and its only 240MB. Try it.

Just been browsing the steam sale and I'm surprised it seems none of you have mentioned Star Ruler - or is it that bad? - it's currently 80% off and I have just enough to bag it if it's worth it!
http://store.steampowered.com/app/70900/

This is a bit dated for this thread but yesterday someone on GOG informed me that Space Rangers 2/Reboot is being reissued with updated graphics and an entire new campaign option which pits you at war against pirates rather than Dominators. Fiends of the series like myself will be waiting in line for it no doubt. Newbies to the series looking for something that has everything EXCEPT sytem crushing specs should have a look.

I've actually got (or maybe had) the originals on disc - may dig them out in the new year! I'd actually like to see an adroid version of them - i'm sure it'd work nicely!

One SR fan to another. Here is the promo and FAQ
http://spacerangershd.com/about/

Is there any place you can buy Space Ranger 2 anymore? I know it got pulled off here, GamersGate, and Steam

you can still get the budget version in uk stores (with 1+2 on the same disc) - so maybe also in the us

WAIT WAIT WAIT WAIT!!!!
Don't get SR 2 Rise of the Dominators!!!
Either get
a) SR Reboot which is SR 1 + 2 plus countless extras missions, graphic updates, and ships or
b) Wait for the new SR A War Apart which is reboot with even newer graphics and a whole other campaigne. Unfortunatly I don't know when it's coming out. The web page says 2012, but thats coming to an end here in afew days, so who knows.

and as of right now Reboot is still available on Amazon.

Star Wars: Empire at War (RTS)