So, Justice League Heroes last gen wasn't exactly the best game. But Marvel Ultimate Alliance (1 more so than 2) proved that games like this can work and are fun. 
 
What would you want to see in a JL game, as far as character selection, gameplay and locales? 

i think that it would be a neat idea to have it where you can choose the incarnation of the justice league that you would want. would you want it when kyle rayner was a member or jordan? or stewart? what about different flashes? and have those different people have at least slightly different abilities, like with the lantern constructs differing with what lantern you have, and different batman costumes for different eras. i know that would probably be hard to do with the lanterns. but maybe they could make it work.

I definitley want an arkham city style Justice League game.

I think the playable characters should be:

Batman because he is the one this all rides on. His gameplay would be pretty similar to arkham only with some new gadgets designed to deal with League level threats.

Superman you can't have a Justice League game without Supes. To play as him you replace grapple with fly up, change the run button to super-speed, detective vision becomes x-ray,ect..

Wonder Woman again simply essential to the League. She would use a more martial arts based style than Supes but not as much as Bruce. Her vunrability to sharp weapons means you would use her braclets to counter knives and gunfire.

Green Arrow because he is on of the easiest to create in the arkham style. It is incredibly easy to imagine his trick arrows serving the same function as Batman's various gadgets.

Flash because he is one of DC's most popular characters and deserves a good video game treatment. He would be one of the hardest characters to make work in this style but if anyone could pull it off it's Rocksteady.

Green Lantern because he is one of the most important member's of the Justice League. His constructs could replace gadgets and he could use the same flight functions as Supes and WW.

Black Canary for almost the same reasons as Green Arrow. Her gamplay would be very similar to Batman's martial arts based combat but her lack of any diversity in weaponry and powers could make her gameplay repetitive.

Those are the ones I think are the most essential and the easiest to put in the world Rocksteady has been building. Here the wons I would like to see but probaly won't:

Cyborg just isn't that closly associated with the Justice League yet. It's a shame he would have no shortage of gadgets.

Martian Manhunter is an extremely important character but I just couldn't imagine his huge diversity of powers fitting in the game.

Aquaman is one of the founding members of the League but his powers just would not work well in an above ground enviroment.

Vixen would simply be a fun character but she isn't very well known and her powers (although really cool) could be a real pain in the neck for the developers.

Black Lightning would be very fun to play as but I just don't feel that he would be one of the developer's first choices.

Possibly for the final battle we could play as Batman in the Insider suit. It would be an epic and fitting conclusion to play as the most powerful character for the final showdown.He would of course have flight, super speed and strength by default. The suit would also allow you to use one power from each character in the game. I listed the suggested powers below.

Superman: heat vision

Wonder Woman: some sort of lasso

Green Arrow: an exploding arrow

Flash: Infinite mass punch or vibrating through walls

Green Lantern: a single ring construct most likely a hammer or shield

Black Canary: canary cry

Cyborg: probaly a laser of some sort

Martian Manhunter: Shape shifting

Aquaman:Telepathy

Vixen: channel a single animal probaly the most powerful one she can use in game

Black Lightning: bolt of lightning duh

Personally, guys, I think more characters as well as a wider array of story could make a Justice League game pretty epic. It works so well for Activision with Marvel Ultimate Alliance 1 and 2, so I'm sure Warner Bros. Games could do well with it too. :) I mean, you can make the teams all about 4 players to make use of XBOX Live and PlayStation Network, as well as showing some unique ways to use the many abilities each member of the JLA shown would be capable of, guys. For example, set buttons for actions as well as many powers used as possible, and how that'd come in handy in the long run too.

@FadeToBlackBolt said:

Characters;

• Superman
• Batman
• Wonder Woman
• Wally West
• Kyle Rayner
• Martian Manhunter
• Hawkgirl
• Green Arrow
• Black Canary
• Red Tornado
• Captain Marvel
• Aquaman
• Orion
• Mister Miracle
• Big Barda
• Captain Atom
• Plastic Man

I'm in full support of your recommendations, but typically the Marvel equivilants fielded a team of 23 so keeping to that baseline that gives you 6 more to work with. I'd place in

- Firestorm (Provides a fire elemental)

- Zatanna (You need some magical representation)

- Black Lightning (Electricity elemental)

- Etrigan (More magic but also demonic)

- Cyborg (DC are gonna be pushing him anyway, and he's a techy)

- Superman Prime (1million. As a kind of super character you get for finishing the game. Similar to Silver Surfer for MUA)