Without any doubt GalCiv2, will bring you in another world and the game is veeery deep and well balanced. Without any doubt u will not regreat it, it's not so easy to learn but if u manage to play elemental it's more or less the same gamestyle.

Both are great games but the two things i would mention to you that might help you decide it this

Sins is real time and a little more modern

Galciv2 is turn based but (as hawawaa indicated) you should get the ultimate version that has all the expansions as well - http://www.impulsedriven.com/galciv2ul

asking which game is better is like asking which flavor of ice cream is better, vanilla or chocolate

personally I found both relatively easy to play and enjoy both depending on what mood Im in

There is a demo for SoaSE that you could try (though it doesn't include any of the stuff from the expansions). Not sure about GCII. That said, I'm not sure if any 4X game can be labeled easy to learn, though if you are getting at Elemental that experience will probably translate better in GC just because its turn based. But I would still try the demo of Sins.

Also, the "complete edition" of Sins is called "Trinity". There is a game of the year edition out there that throws people off sometimes, but that is only the base game, no expansions.

I would go with GC2, No 2 games of it will ever be the same.  The AI is very well done.  I find it quite amazing how you can "play" one AI against another diplomaticly.  I`ve had the AI crush me in a war, At the last minute was able to diplo another AI to attack my enemy.  I survived with 2 planets and recovered to win the game.  It was quite exhilarating for a 4x game.

I own the sins trilogy, I can`t get into it for some reason.  It just seems simple to me.  Build econ structures in planet grav well`s, Move fleet thru space lane to next planet.  It seems to revolve around choke point planet`s.  The space battles can look really nice, I find the game to be very shallow and uninteresting.  The music quality in the game is terrible.  That may seem like a strange complaint against a strat game, It`s important to me.  It`s not the music itself, It sounds like it was created with a casio keyboard.  I wouldn`t recommend sins.  

Neither, Sword of the Stars (and it's expansions) is clearly superior to both.  Especially GC2, which becomes trivially easy to beat due to piss poor AI implementation on the strategic level.

Then again I don't know what the going prices are for any of those games, so maybe you can afford to just get all of them

Sounds like everyone has their fav = p I guess its a tough question to ask cuz everyone will feel differently. Like if u were to ask me best MMO I'd say EQ1 everytime! I just downloaded the GalCiv2 demo so going to try that out (prolly shoulda checked on demos before asking huh?). Both games do look interesting though. Thanks for all your input.

Depends on what you're looking for.  Sins of a Solar Empire takes the pacing and structure of a 4X turn-based game and implements it with the mechanics of a real-time strategy game.  GalCiv is of course a TBS in its purest form.  Definitely try the demos and see which you prefer.  Can't go wrong with either.

Human strategies continue to evolve and grow after the game releases, while the AI strategies do not.  Combined with the fact that AI's cannot adapt or learn and will repeatedly fall for the same tricks over and over, this eventually leads to a situation where players develop "meatgrinder" strategies that let them defeat much larger and stronger AI's with minimal casualties.

It happens in every game, it's just a matter of time. 

do you like sp or mp?  If mp, SoSE.

I enjoyed galciv2 for SP (it has no mp).  I loved SoSE to play with my buds.  We've had many fun nights just playing away against ai's together.  I've played some in SP, but I really prefer the MP co-op.  So, i guess its simply situational.  If you the solitude of playing against intelligent ai, I'd say go with galciv2, but SoSE is a close 2nd.  If you like co-op at all and have a few buds that would play with you - there should be no question - pick up SoSE. 

SotS has 3 expansions actually, or 2.5 if you don't count Argos as a full one since it didn't introduce a new race.

But yes, the game play is dramatically improved over the initial game.

My comments on the GC AI have more to do with the decision to go with an open space design, which the AI simply could not handle.  Brad even told me why back in the old forums, the AI didn't look at everything in it's scanner range.  Meh, if you developed faster fleets, you could run rings around the AI, getting it to chase dummy fleets (which you let it catch) and then smacking it's planets with your real fleet which it never saw.  As far as I know this flaw was never rectified, but it drove me nuts.

Also you could ignore any military ship production until after your enemy got troop transports, meaning you could almost always develop a much better economy/tech base, and then when someone did decide to take a shot at you, mobilization was pretty easy, and your ships were almost always superior to whatever the enemy could throw at you.

I dunno, I enjoyed G2 for a while, but as someone mentioned, once you got the hang of it, the flaws in design really crippled the AI as far as I was concerned, and the game became a lot less interesting, because you'd already pretty much seen everything, to beating on Masochistic (or whatever the highest diff was) became an exercise in tedium.  I suppose *all* games eventually get there?  Well not for me, but GC2 definitely got there faster than I wanted it to.

Of the games listed, Galactic Civilizations 2 is my favorite, but they're all far from perfect.  In the end, it really comes down to what you like/want most in a 4x game.  Here's my quick overview: 

GalCiv2

Pros:  Great AI.  Good empire-builder.  Diplomacy actually works and makes sense.  Excellent ship design.  Insane amount of game customization options allow for endless re-playability.  Epic-sized maps. 

Cons:  No tactical battles.  Economy wonky and sometimes hard to figure out.  No multiplayer (for those who care).

SotS

Pros:  Total War-style blend of turn-based empire management and real-time space combat.  Unique races with genuinely different methods of interstellar travel.  Battles work well and look pretty. Streamlined colony management.

Cons:  Empire-building aspects light and shallow; the game is overly-focused on combat. 

SoaSE

Pros:  Massive scale (large maps, large fleets, etc.).  The races are fairly well-balanced.  Decent AI.  Battleships as "hero characters" with upgrades.  Nice visuals.  Pirates can make matches interesting. 

Cons:  Not a true 4x title; feels more like a standard RTS with "4x light" elements included.  Only three races.  Battles can feel a bit static sometimes.  Pirates can be a pain in the ass. 

Really, all three games are quite enjoyable in their own way.  They all do a lot of things well, and they're all made by companies that have a reputation for standing behind and supporting their product.  Again, it really boils down to what exactly you're looking for in a space strategy title.   

Is the GalCiv2 demo a fairly good representation of the game?

Just asking, cause I loved MOO and MOO2 (I stayed away from MOO3...which was a good choice says a friend of mine), but I just couldn't get in to the GalCiv2 demo.  It seemed that nothing ever happened, and the "universe" seemed really really empty. 

If I didn't like the demo, is there any chance I'll like the actual game?

I don't even remember what the demo was like, but MoO3 is actually quite enjoyable these days.  However, you need the user patch (Bhurics) and one of the developed mods to get anything out of the game.  Staying away from MoO3 during it's first couple years was a good choice though

In my opinion none of the games mentioned here are remotely like MoO or MoO2, other than the setting, they all have significant differences from the core mechanics of the MoOs to make each interesting in their own way.

If you like having a greater importance on ship design and tactical combat (though real time, but pauseable) then go for SotS.  If you like more diplomacy options (though sometimes they are too exploitable in my opinion) go for GC2 (but realize there is no tactical combat, and ship design is limited).

I'm sure someone else can comment on SoSE, I cannot because I never played it.