1. Superman
Obviously
2. Wonder Woman
Also for Obvious reasons
3. Martian Manhunter
He's a staple of the team, he should always be there probably no matter what.
4. Aquaman (90s - early 2000s era)
I feel he seems pretty relevent judging that he controls 70 percent of the Earth.
5.Sandman (Daniel Hall)
6. Hawkman
7. Elongated Man Post Crisis Pre Flashpoint continuity
He died during Fifty Two, a nice, warm conclusion to his arc in Identity Crisis, but I think his character could be explored in a different direction
8. The Spectre
Used with the same frequency as Grant Morrison used Big Barda and Mister Miracle, not a a lot
9.Hourman
10.Animal Man
11. Zatanna (Satilite Era Iteration.)
12. Black Bat (Cassandra Cain
Also, like The Spectre, used scantly
Notes
I felt Batman (Bruce Wayne at least) is too tangled into his own mythos to be on the Justice League, and then I thought of having Dick Grayson on the team, but I read a comic that explained why he wouldn't be on the Justice League, I think it was the first issue of Brad Meltzer's run on Justice League of America.
Also I originally wanted to put Wally West Flash on the Team, but I've never really like the concept of the Flash, as much as I liked the character of Wally West himself, because I felt The Flash being on the team of the Justice League felt sort of redundant or him even existing at all seemed pointless, being Superman already has super speed, and yes I know that The Flash has the Speed Force, but why can't Superman have the Speed Force?