Have tried to include as many options as I could, mostly among characters usually associated with being Justice League founders/prominent members of iconic lineups. And I'm including outliers like Blue Beetle simply by virtue of him having a film out soon. But I'm almost certain my list of options won't be exhaustive and someone will want to include a character who's not present.
I've given it some thought and here's my lineup:
Superman
Wonder Woman
Flash (Wally West)
Green Lantern (John Stewart)
Hawkgirl (Shayera Hol)
Green Arrow
Black Canary
Martian Manhunter
The big highlight here is that I've switched out Batman for Green Arrow, as I feel Batman might need a time-out from the DCEU while the Pattison/Reeves series is still running, and also because it'd be a great opportunity for Ollie to get his due. Also switched out Aquaman for Hawkgirl, because I'm a huge DCAU fan and I feel maybe it's time to rest Aquaman too for a bit after the Momoa version is done. Keeping Wonder Woman though, since I feel you can't get rid of two-thirds of the Trinity for a JL movie, but I'm kinda on the fence here.
Who would you like to see?