Hello,
I would like to ask if you know any space rpg (I know about Mass Effect so it doesnt count :) ), which you could recommend as a great, complex game with fun gameplay, great story and big world to discover? Or at least with one of this characteristics? :) I like role-playing games, but when i fount Mass Effect, I realised, that I didn't play at any other Space Opera ever.

Any ideas folks?

There's Alpha Protocol which, apparently, is an action RPG. No idea whether it's any good. Knowing Obsidian, it was probably buggy during release and patched after initial reviews, which can affect metascores and such.

http://www.gog.com/en/gamecard/starflight_1_2

maybe star wolves, but never played that one.

There are other sci-fi RPGs but most of them are very old, sadly. Classic Tolkein-esque fantasy just sells better, for whatever reason. Personally I am baffled by it, but if you cruise an RPG fan site like RPG Codex or RPG Watch you will see people say consistently that they only want a traditional fantasy setting.

Anyway... the X series has RPG elements, but is mostly a trading/space sim game. There are MMOs like Star Trek Online and Eve Online. I think Space Siege was an RPG, but was universally panned.

Not space-based though - modern-day espionage / special forces, innit?

Knights of the Old Republic is probably your best bet.

Sci-fi CRPGs have always been rare. Albion, Knights of the Old Republic 1-2, Black Market, Star Wolves, Space Rangers, Precursors, the really old Battletech CRPGs (The Crescent Hawk's Inception & The Crescent Hawks' Revenge), System Shock 1-2, Deus Ex, Shadowrun (SNES & MegaDrive, different games) & Planet Alcatraz are the only ones that I can think of right now (not all are set in space, and not all are pure CRPGs, many are hybrids)

You could also make a case for the Might & Magic series & the Wizardry series, but they are mainly fantasy games, with a slight sci-fi twist.

Star Wolves (1st anyway) is great. Stunning backgrounds, great graphics. Deep gameplay.
It's like Homeworld, on steroids. Albeit a but buggy.... 2nd one is supposed to be awful though...and Not sure on the 3rd one..

I can only think of one off the top of my head that hasnt already been mentioned here, and that would be Space Siege. Kinda oldish and requires a decently good computer. I enjoyed it but it wasnt really received well by the gaming industry and whatnot. Only place that sells it digitally that i know of is Steam and its 15 bucks there. But definitely recommend KoToR 1&2. Two of my favorite games of all time.

Edit - Forgot link.

Space Siege on Steam -

http://store.steampowered.com/app/10530/

It was basically Dungeon Siege in Space. Not bad, but also not very good. And certainly not what I call an RPG

For space opera games, you cant really miss Wing Commander series.

If you want something that takes place outside of a cockpit, there is always star wars games, but I would also recommend Precursors

Don't get Space Hack or Space Siege, they are not very good and can not really be said to be RPG's. If you want a Diablo style sci-fi ARPG, then I would instead suggest Greed: Black Border.

KotOR 1 and 2 are the obvious choices.

Besides them, the only thing coming to mind is I know there are a few jrpg's that fit the bill of "space" and definitely "opera", but won't be very much sci-fi at all. Garden variety of guns, swords and big-eyed bikini babes. Can't remember the names though.

The rest of what's been mentioned, isn't anything at all like Mass Effect... and neither is this, but I really got a kick out of MechCommander 2. Available as a free download somwhere around the nets.

Space Pirates and Zombies is a kind of RPG too.

Yep, it's a spy RPG (only one I know of) - great game, though.