I was wondering if anyone knows of any space rpgs where you can for instance pilot your own space craft through an open ended world kind of like a space simulation game I guess. Also I don't care if its single or multiplayer or even mmo i guess.

Eve for MMO
Freelancer for Single player and Multiplayer.

This game is going to be great. :)

http://www.infinity-universe.com/Infinity/index.php

yup freelancer for single and eve, jumpgate, or vendetta for mmo!

Vega Strike is a fine alternative to pay game its more of a sim though http://vegastrike.sourceforge.net/. Even though its in beta its still perfectly fine to use and there are even some mods out for it, including http://priv.solsector.net/ a remake of the 1993 game Privateer and you can make your own quite easily. As for multi player EVE is the most popular with the most community I would suggest it http://www.eve-online.com/. There are others like jumpgate http://www.jossh.com/join_today/index.html, dark space http://darkspace.net/, rise http://rise.unistellar.com/, Star Sonata http://www.starsonata.com/, and vendetta http://www.vendetta-online.com/. Forgot a single player game http://www.fsoinstaller.com/ technically its abandonware so this is within the rules.

Im not much of this kind of game but err...Space cowboy online?

space cowboy/flysis/whatever the hell they call it now is more of a arcade flight combat sim on grounds with something you would see on a console what he is looking for is more like the http://en.wikipedia.org/wiki/Elite_(computer_game) series of games something like if he went the pay route and http://en.wikipedia.org/wiki/X%C2%B2:_The_Threat X2 The Threat and X3 Reunion http://en.wikipedia.org/wiki/X%C2%B3:_Reunion. Also if your looking for a more realistic(like to the point of tedium) try http://www.3000ad.com/site/free_games/ Universal Combat its a huge game not really a space trading game like Privateer or Elite more of an RTS(real time stratagy)/TBS(turn-based strategy)/RCS(realistic combat simulator.) um ya thats about it and my thoughts on space cowboy its a good concept but they need to get allot of stuff better I tried it and it didn't hold my interest more then a week. Oh crap I forgot about a couple of free games in my post above http://www.monkkonen.net/wazzal.php Wazzal Its a great game 2-d so its likely your rig can handle it I also recommend notrium great survival game were they stick you in a setting and make you just run with it on your wits alone. http://www.pardus.at/ Pardus is a pretty good free game made solely for browser not much I can say about it other that its free and its got practically no requirements.

Spaceforce: Rogue Universe

I got bored of it pretty quick but space looks so pretty in it.

Freelancer is a nice option even though u don't have complete freedom of movement... Privateer II, really oldie, was an awesome game and, until now, it was the best I found.
U also have Freespace II but I haven't tried it yet (even though it's also old) but should be good as well. All these games have nice graphics and their control is very similar, so if you're comfortable with joystick control these are my choices.

Not long ago I saw a demo of Star Assault (recent game) and it seemed a type of game like the ones above.
There is also Tarr Chronicles, but haven't tried that one either - http://www.quazar-studio.com/tarr/eng/index.html. Accordingly to them it's a "space-action game with strong RPG elements. Alongside his comrades, the player will experience all the trials and suffering of people lost in the murky reaches of space. Only the strongest will make the impossible happen and return to their homeworld."

And those were my 2 cents ;)