The ORIGINAL Megazord runs the Power Rangers gauntlet

[Kuro]

The OG Power Rangers run the Megazord gauntlet.

Jason, Billy, Trini (God bless her), Kimberly and Zack reunite in the original Megazord. They must fight through every single generation of Zords (combined). How far do they make it?

After each battle, they have their energy restored and a fancy new one-liner.

Bonus - they have the Dragon Zord and Titanus assist

[Cyke]

The OG Power Rangers run the Megazord gauntlet.

Jason, Billy, Trini (God bless her), Kimberly and Zack reunite in the original Megazord. They must fight through every single generation of Zords (combined). How far do they make it?

After each battle, they have their energy restored and a fancy new one-liner.

Bonus - they have the Dragon Zord and Titanus assist

In-story, the original Megazord is supposed to be obsolete to everything up to the Lost Galaxy zords. For the most part after that, it should be relatively much more even.

That's the weird thing about Power Rangers. If this is a normal, sequential gauntlet, they should lose the first few fights and then have much better shows against later tiers. So a gauntlet might not be the best way for them to prove themselves.

I'm gonna go out on a limb though and say the Time Force (Blue Mode) and Storm (Lightning Mode) Megazords via speedblitz, among other zords. The original was built much more like a tank, and even the original rangers received more agile zords later on (Red Dragonzord, Red Ape Zord, the individual Shogun Zords, etc).