I think it's Batman. Not just because he's my favourite but because every time he barks orders, it's like no one has the guts to question, even Superman follows. But yes, it would be nice to think all of them as equal. But I also think that it's good they have a leader or the "Senior Members" as Fire addressed Flash, so they'd be coordinated, like how J'onn and Mister Terrific deploy them on missions. :D

there are two leaders really, batman and superman, (but mainly batman)

I don't know. I have always thought that batman was leader

Batman and J'onn seem like the leaders. And some times Superman has something to say.

Superman is the Team leader whether we like it or not.

I think it is shared between batman, superman and wonder woman.

Um. Me! I'm obviously the leader. Superman is just retarded(and he owes me $10,000) aquaman is gay, flash is too fast, green arrows busy with his affair with black canary, green lantern is with his space pals too much, martian manhunter has his hands full with "HELLO MEAGAN!!!", and Wonder Woman doesn't wear pants. Which leaves me (and some other bazaar superheroes, but I'm batman.)

In the old continuity, Superman was the leader. But in the new 52 continuity, Batman seems to be the leader of the Justice League.