I was about to post about this, the last few games I've played the Thalans have completely dominated, they have colonized twice as fast as the other races (including myself) and in my last game (teamed to me) they had a overwhelming military and caused the surrender of all but 3 of the other NPC races in quick succession.  Their influence victory is practically assured.

It's been awhile since I've played GC2:TA with any frequency, but before I don't recall the Thalans to be so powerful.

The past games were on challenging or tough difficulty.

Perhaps some balancing is in order, but until then, I think I'll leave the Thalans out of my games or play as them.

I think that the problem is that they combine a massive production boost with powerful techs and imps. It is not a good idea to charge slightly more for really great improvements, then make that production increase moot by boosting a race's access to factories.

In my games, it seems like the Iconians always do very well. And I hate them, they declare war on the weakest civilizations and call themselves good? Bah!

The Korath are cute, but they ALWAYS lose.

Terran and Altarian have been doing well in my games lately... cause nobody attacks them guys!

In my last game Thala was the only Thalan planet and when I took their Hyperion Matrix, I was happy.

Hehehe... The korath always seem to dominate in my games... (so far). The Drengin dominated in my last game... but after a long bloody war I kicked their butts with the planets I stole from the yor (and the techs I stole). Although it did disturb me when I spied on their planets and they had like no improvements built anywhere even though we were some 8 years into the game (game time!).

That sort of depends on how isolated the turf is. If it is on an Immense map with tight clusters, a civ starting out like that might still end up in the middle or lower ranks because it had little or no contact with the other civs. At least with tech trading on, this can lead to a situation where the relatively high-pop isolated civ has plenty of warships built, but they are all seriously less advanced than the best hulls coming from the civs where folks have better techs on account of trades.

Good for you, mate.

I have to also throw in my 2 cents about the Thalan.  I've played 4 ToA games so far, and each time the Thalan are the #1 race in the galaxy.  They even wiped the floor with the Dread Lords in one game.  The Dread Lords had some successes early on, but the Thalan were able to produce maxed out fleets comprised of multiple battleships and dreadnoughts at a near impossible pace, and the DLs never had a chance, really.

What really annoys me about them is that they're very arrogant.  Once they've established their dominance, they talk down to you even if you are on friendly or close terms with them (perhaps all species behave like this, but I wouldn't know because the Thalans are always #1!).  My last game I was the #3 race in the galaxy, close relations with the Thalans, and I had a military force that could eradicate them, and they still were very condescending.

It's also very expensive to negotiate with them.  It seems like it costs twice as much to get something from them than the other races (this is with maxed Diplomacy tech and the Galactic Achievement that boosts your Diplomacy).  Again, perhaps all races behave this way once they become uber-powerful, but I wouldn't know since none of them have ever achieved it.  It's always the Thalans.

It's this kind of post that makes me think there really is no 'strongest' AI civ. The map is the game, and there's a lot more to a map than the core decision code for a given AI. And then there's the business of how different playstyles will get very different things out of the same type of map.

It's part of how the game has had such fantastic replayability for me. For many, many games, the Torians were the bane of my existence. Briefly, I actually got to struggle with successful Drengin and once the Korath were a real power. I mostly play as Thalans, but when I haven't I've seen both the Fuschia Blob of Doom and what looked like a bunch of semi-hibernating bugs from the future.

I'm not entirely sure this is true. I typically build up a large military whether I intend to be a warmonger or not, just to scare off aggressive AIs. Yet I've varied it up sometimes and gone the no-military economic giant route, and yet the same races still seem to do well or poorly. True, they'll be more aggressive towards me - but this usually just leads to "Sleeping Giant Syndrome" where I use my economic might to build up a fleet and crush the aggressor.

In general, AI performance seems mostly based on starting position, but some races consistantly do stronger then others. The Arceans (in DL) are usually a power and all the evil races but the Korx never do well. The Korx actually used to do well but now they always get ganged up on by the good races. The Thalans seem to vary in power, the Terrans are a joke, and the Torians are very, very strong. I still think that this:

is the heart of it, though, as for everything I just said there's at least one exception in a game I've played.

I was fighting against the Zylons, a custom race with the Yor tech tree.  They were the leading galactic power and I wasn't conquering them very quickly because they had better weapons and I had gone for a starbase strategy and well, you know how long it takes to get enough constructors in one place for the attack bonuses.

So then the Yor notices that the Zylon military power is beginning to crumble from all the suicide sorties and jumps right in there with a backstab, despite the economic and research treaties they had going.  They even got on the communicator to let me know about it, smug gits.  I honestly couldn't get transports in there fast enough to mop up the undefended planets.

Sometimes the AI just doesn't seem to realise that their lead has evaporated.

STOP WINING I MAKE SURE THEIR IN ALL OF MY GAMES BECAUSE THE ONLY WAY TO BEET THEM IS FIGHT THEM IT'S BETTER THAN THE WIMPY DARK AVATAR PLEASE DON'T DO TGHAT AGAIN IF YOU DON'T LIKE THEM DON'T INCLUDE THEM BUT DON'T MAKE GALACTIC CHANGE THEM IF ITSD UNFAIR MAKE THE OTHER RACES BETTER. PS. I CANT BEAT THEM THATS WHY I STILL PLAY AND STOPPED PLAYING DARK AVATAR AND WENT BACK TO THE DREAD LORDS UNTILL TWILIGHT OF THE ARNOR.X IF ITS TOO HARD PLAY AN EASIER LEVEL.

I figured out how to weaken the Thalans for a time, Customise the weaker races. This actually causes an encroachment on the tThalans by the customised races.

Yes, I agree, sometimes they research really well, for example improving logistics so that they can get their fleets big enough to take on the human.  If they get left to last they can easily master one of the weapon trees and one of the defence trees (to match your choice).

But sometimes they research all sorts of things that they don't need, like Warp Drive when they desperately need to cram weapons technology.  It's not going to matter how fast their ships can move if they're going to explode without so much as denting the shields of an enemy ship.  Personally, I only put engines on my ships if enemy ships are going to be fast enough to avoid interception, and when I do research propulsion, the standing speed bonuses that affect all ships are usually enough for me.

One of the factors holding back research is the continual upgrading of facilities.  Every time you upgrade an existing building, the cost to upgrade increases.  It isn't a huge amount but by the time you get all the way up to Discovery Spheres, you'd almost be better off demolishing and starting from scratch.  I myself tend to turn off all automatic upgrades and do the upgrades manually when every second or third new building comes along.  And sometimes I will demolish some of my existing structures so I'm actually producing the same amount of research on a planet but using fewer tiles to do it and paying less maintenance on buildings.

The AI really needs to get the idea that more buildings, especially ones which suck maintenance, is not always a good idea.  Ultimately there are two things in its budget which will force it to set the industry slider to less than a hundred percent, and that is colony maintenance and ship maintenance.  Ships at least can help it defeat other civs, or stave off attacks at least.  Buildings are great big targets waiting to get washed away by Tidal Disruption.

I routinely turn Surrender off when launching a game, if it isn't already off.  Obviously this means that my enemies can't surrender to each other and create a much bigger combined threat, but on the other hand they don't make me more powerful in the blink of an eye either.