Where is Master of Orion 3? I know, it's possibly the worst part of the series, but it hasn't been included. Maybe it will be released later, as a separate 5,99$ game.

There is no Master of Orion :)

MoO3 isn't a real Master of Orion ;)
Didn't think that many old fans from MoO1+2 would buy this shit. ;)

MoO3 is a disgrace to the name. So while it certainly is old it's far from being a "good" old game.

There is a full conversion mod called "Tropical" that drastically improves the game. If Gog could include the mod, it would be worth $5.99

Master of Orion 3 was a collection of excellent ideas that were badly, BADLY executed. I once heard it described as a spreadsheet on amphetamines, and that's not an illogical conclusion.
Anyone looking for more MOO-iness should take up the heir apparent to spacebound 4x, Galactic Civilizations. Not a series that GOG can really sell, but still. Similarly DRM-free and available for (reasonably!) cheap.
Or just keep playing MOO and MOO2 compulsively until you drive yourself into a nostalgic stupor, like I'm doing.

Your're not missing much by not having MOO 3.
Yes, the Tropical mod improves the game, but ever the improved game is vastly inferior to MOO 1 and 2.
And I echo the cheer for Galactic Civilizations. That is the real sucessor to MOO.
There was a fun Space Conquest game called Imperium Galactica 2 which I would not mind seeing GOG get.

Agreed. but "Distant Worlds"( out 2010-03 ) is a worthy competitor, a bit closer to the original MoO1/2 feel .

I partly agree on this. MoO3 was ambitious and Quicksilver had very good ideas about it so it could have become great game. Too bad it was ruined by publishers. There is an article (probably still somewhere) where Lead MoO3 dev talked about the development cycle of it. With publisher changing three times and each coming with their own requirements, platform targets, budgets and release deadlines. They just ran out of time as they had to spend time on rewriting parts all the time due to requirement change.
I have the MoO3, bought on release date. And while it really does not stand up to the name and quality just was not there, I don't think it was really that bad as it is generally said. It's not good, but it's not really that bad either. I'd say it's playable and you can enjoy game or two, but once you put it aside, there isn't really anything that would bring you back to it.

i don't see this coming, as everyone else pointed out.. it wasn't plain bad, there were some cool ideas in it, but they were awfully implemented... not to mention the interface was light years far from being not only user friendly, but even playable at times...
i'm in with those who second galciv as The 4X space game lately

If GalCiv didn't feel like it was just a reskinned version of Civilization 2/3 I'd probably recommend it. It's about as much a worthy successor to MoO as the new King's Bounty games are to Master of Magic.

I agree with Winged. GalCiv is good, but not like MOO1+2. In galciv you can make your ships look lots of different ways, but the weapons and armor are just generic laser +1, +2, ect. The combat is auto resolve because there's no real special abilities. Combat and ship making in Moo2 on the other hand is intensely tactical and a real highlight of the game. You can go for diplomatic victory in MOO2, but it's the quick and less fun way.

I keep hearing on how MoO3 is one of the most reviled games of the genre - I remember asking on a Mac forum once if it was worth buying from the bargain bin at a computer store I used to frequent, to which all of the veteran MoO fans answered with a resounding no.
Heh, a joke that still makes me chuckle was when someone on said forum called it "Master of Micromanagement 3".
Reminds me of a similarly titled 4X game that came out the same time as MoO3, Pax Imperia 2: Eminent Domain. It was the first game I ever saw that was able to play itself - I could set my Viceroys all on autopilot and it would just churn away happily, without needing any input from me at all.

Fixed that for you. You're welcome ;)
Seriously, though. I bought MoO 3 after falling in love with the first one without reading any reviews. I tried so hard to like this game, and I'll be the first one to admit it had a lot of things that would have been fun to see in the previous games, but in the end it was like trying to command an empire through your tax forms!
Finally managed to track down MoO 2 shortly after that. Had to ship the copy overseas from some obscure internet company, but it was well worth it.