This topic is basically an examination of which races are the best ones to have as allies. Both for the actions they let you do, and the benefits you get for having them in the federation.
Andors: Andors have a lot of neat actions, and are relatively easy to get into the federation. They give lots of ways to boost the planet stats of other races and a backdoor into getting the Acutians into the federation (which might be broken, I don't see the option in their political actions). Unfortunately, they offer no warmongering options and can only offer some of their bonuses at any given time. Thankfully, those are fairly easy to change around.
Skylaxians: The Skylaxians are sort of an all round race. You can pretty much get them to do anything you want at any time for cheep. They're also really easy to boost influence with and get into the federation. I've generally found that you're almost certainly going to be either forming the federation with them, or getting them in it right away. They're only real special action is that they can backdoor any other race into the federation. Military wise, these guys tend to be one of the strongest too.
Peltians: I've found that the Peltians are almost identical to the Skylaxians, other then that they have a unique currency. Their only real special power is to create the federation for safety, but since the Peltians, Skylaxians, and Andors are really easy to get into the federation anyway, it will almost certainly be faster to create the federation with two of the others, then bring the third one in after the fact. Bring em in, or kill them, and after that you probably won't notice the difference.
Evucks: These guys are designed to be annoying to deal with no mater whether you're going to make friends with them or fight them. They have higher costs to do thing then the other races, which get even higher the more you do with them, and can take out a third of the solar system if you try to kill them. Even their bribing system is a pain to play with. On the up side, they have some nice powers that let you ruin enemy planets quite effectively.
Acutians: These guys have the most options and powers of any race in the entire game. They can destroy planets, damage other planet's environment or economy, and even backdoor other races into the federation! The downside is that they can only do a handful of them at any given time. If you want to manipulate what is available, you're going to need to control a construction outpost. That said, this manipulation will quickly get you all the influence you could ever need with them. These are probably my most recommended ally, given just how much they can do for you.
Burlusts: A very meh race. They've got their own currency, like the peltians, but very few special options for them other then ways to get that currency. Once more, they've got a special federation creation decision, though how useful it is to use depends very much on the game. You're going to need some great trading opportunities to make it worth while over just creating the federation with two races and then bringing the third in later. They actually have fewer actions you can take with them then all other races and you're very unlikely to notice a difference when you have or don't have them in the federation.
Boarines: They've got most of the same options as the Skylaxians and Peltians, except that you can only do certain ones at certain times. Very annoying to deal with, and the only unique power they bring to the table is the ability to make two other races either like each other more or like each other less. This is certainly a useful power, if you've got the skylaxians or acutians to bring other races into the federation with. Unfortunately, they end up being rather underwhelming when compared to even the basic races, since what you can and can't do with them at any given time is so limited.
Thoraxians: These guys are just a pain. You can't form the federation with them, they're really tough to get into the federation, and if you do get them into the federation, everyone else starts liking you less and less over time. They give you no real powers or benefits, and have a somewhat annoying system for locking out what is available and not available at any given time. Thankfully, it's much easier to manipulate then the Boarine's system. Even worse, their options are only slightly better then the boarines, with no real special actions. Unless you're trying to get every race into the federation, you may as well kill these guys.
Overall, my rankings are:
Acutians > Andors > Skylaxians > Evucks > Boarines > Peltians > Burlusts > Thoraxians
I think it would be really nice if Arcen could add some more special actions to the races that have so few options, mainly the Thoraxians, Burlusts, and Peltians. Though one or two more powers for the Skylaxians and Boarines would be nice too.
What do you guys think? Do you agree with my assessment? Have I forgotten anything? Do you think others are more useful for different reasons? Anything you think that could be added to make certain races more interesting and better allies?