I find the relationship names "tolerable"

, but I agree they could perhaps be improved. Right off-hand I can think of Civ4 that had pleased and friendly, but that doesn't seem like much help. I can't help but think Gothars' suggestion of Solidary is just way too close to "Solitary" to work.
Neutral->Favorable->Welcoming->Friendly->Cooperative Hmm... Have to keep it in context. Space factions in desperate times where many resources are scarce. Well, something to keep in mind is that these terms should work for both when you are a single fleet, and when you are running a faction yourself.
Some brainstorming later...
Perhaps flipping favorable and cooperative?
Cooperative->Welcoming->Friendly->Favorable
That would put Cooperative and Suspicious opposite one another, which I think fits. Welcoming-Inhospitable and Friendly-Hostile also work as opposites, already. Favorable and Vengeful don't mesh so well... Holding judgment on Favorable for a sentence or three, perhaps Vengeful isn't a good choice? Hateful seems like a suitably strong word, but doesn't seem to quite fit the mold. Forsworn randomly popped into my head for some reason lol

. Hmm... turning to Favorable, it just doesn't seem like a strong enough word to represent the final level of positive relation. I had "Close" flop into my head, but, like Hateful, it doesn't fit the form of the other relation levels. Allied has come up in this thread, but it doesn't seem like a state of relations that would come from anything less than joining the faction or some sort of treaty between your faction and theirs. I've been assuming the top relation level doesn't require practically or literally joining the faction to reach. If it does, though, then Aligned could be used.
Cooperative->Welcoming->Friendly->Aligned
Suspicious->Inhospitable->Hostile->Hateful
I guess Vengeful could work if it wasn't a level a faction would typically stay at if they got their revenge on you or whomever.
