With those particular lineups, Outsiders due to J'onn and Metamorpho (though I'll note, that was never actually an Outsiders team; some of those were only perspective recruits).
5 minutes at the beginning of the Chuck Dixon "Batman and the Outsider's" run.
DC had advertised the cast, but then decided to change the team, so rather than have someone advertised not show, they had him show up in the book but decided not to join, and just helped Batman on the one mission.
Likewise, Aquaman there in the back was never a member at all, he was just a prospective member in the "Outsiders: Five of a Kind" miniseries with an issue about him, but he decided it wasn't for him.
id go with wildCATS on this one. im ignoring MM and aquaman unless a post lists them as being part of this fight since i dont really count them as outsiders. [its like counting Quake from the secret warriors as an avenger cuz she helped them once..ehh.. even if they were considered, they weren't official]