In an older thread, I once asked what pairings and groupings of popular heroes we hadn't really seen. There are endless permutations.

I was thinking about that thread and then a more interesting question popped into my head: what does the actual relationship tree of the Justice League look like? Over the years and various lineups there are obvious close friendships, but then there are members who get along on duty yet don't seek each other out beyond that. And then there are characters that either don't interact unless they have to, or have a bit of a grudge.

Friends:

Hal and Ollie (and Dinah)

Ralph and Barry.

Barry and Hal.

Wally and Kyle. Connor with both.

Clark and Bruce (over time).

Aquaman and J'onn.

What about the Green Lanterns with each other? Who among them are better friends?

Friendly coworkers:

Wally and Superman. Wally comments in Funeral for a Friend that he never really knew the guy well, and it wasn't until Secret of Barry Allen that he hung out with Clark back in Smallville. But they frequently helped each other out on adventures and never clashed.

Barry and Batman. The forensics definitely brings them together in mutual respect even though their personalities and abilities are pretty opposite.

Wonder Woman and most: I'd say that this one is trickier because she hardly has a secret identity civilian life and is socially intelligent enough to get along with everyone, yet I don't think she's actually friends with any. The closest she comes is seeking guidance from the other two members of the Trinity, but that's only one part of friendship.

Aquaman seems to get along with the Hawks and Diana when on the job.

J'onn seems to converse more with Clark and Bruce on the job, though I'm not sure if that's accurate.

Zatanna seems to have gotten along with most. (Especially the guys, hehe.)

Strictly Coworkers:

Hawkman and most. He seems to enjoy his alone time.

Hal and Bruce are definitely only coworkers. Neither is inviting the other over for dinner.

I'm not sure if Barry and Ollie actually dislike each other enough to go in this category or if they eventually got along enough to be friendly acquaintances when hanging with Hal. Buried, what say you?

Wally and Batman. I think because he grew up with Dick it's too weird to socialize with him (on top of the fact he's Batman).