What if there were a JLA video game like Final Fantasy Tactics Advance?
It would allow you to make teams of 6 from hundreds of DC heroes who have been on the JLA. You could also give skins to different characters.
It would be for DS, Cell Phones, X-Box Live, PS3 Online, etc. Most versions would allow for online competitive play between players.
The Story Mode would start with an invasion of Earth by Darkseid and would have the JLA travel across space, time, and alternate dimensions to gather the tools necessary to stop the invasion.