Simple fighting game roster if you don't want to use megazords: Red and the team, and then the 6th. Separating the 6th ranger from the rest because they either operate on their own often enough (White Dino Thunder, Quantum Ranger), they fight in a separate style from the rest of the team (Note: Only applicable to teams who operate in a uniform manner, like Samurai Gold or Green Samurai Ranger), or they're just too cool to be lumped in with everyone else (Like the Black Lion Ranger or Dragon Ranger).

Wii is dead. Put the game on Wii U, 119 rangers is to much to fit on a DVD anyways. A Blu-ray? Good size

I'm just saying Wii because the Dice-O models don't look to great.

A Marvel: Ultimate Alliance style game featuring every Ranger in existence would be pretty sweet.

I think that'd be a bit much. Lots of characters would be repetitive (SPD, Lightspeed, and Time Force characters' move list would be shoot guns, and shoot guns again, for example), others would be bland and boring (MMPR would be vanilla as hell to use, and in a dungeon crawler, variety is the spice of life), and etc.

While I wouldn't be against a MUA style game, there's just not enough to go around to include everyone (Which is why Super Legends made the decision to only include 2 per series)

I think the most realistic approach to having a ton of rangers in one game would just be to expect a mediocre game where they all have really generic movesets. Like Dynasty Warriors.

Screw that noise. They can make this an epic.
Like a Ranger RPG or something.

I love the Dynasty Warriors idea, Brain. They can fight through Angel Grove, Outside the Command Center, Onboard the Megaship, Terra Venture, Inside SPD HQ, The Wind Ninja Academy, and on and on. I love this idea. And the enemies can range from Putties, to Tengu, all the way up to Moogers. You could even have Zord excusive levels. Where you fight has a season's megazord against a horde of large baddies. The Super Giant Moogers in Samurai lend itself to that concept very well.

Dynasty Warriors: Mighty Morphin' Power Rangers! Coming soon!

As long as the zord battles are better than what they were in Super Legends...

Oh hell yes. I hated that timing button pressing BS. In Dynasty Warriors: MMPR they'll be like the normal battles. You against a horde of super monsters.