[MattEmily]

In Mighty Morphin' Power Rangers... our heroes are just called Power Rangers, right?

yes but in later seasons they're given the distinction of Mighty Morphin Power Ranger.

In Power Rangers ZEO... our heroes are designated as ZEO Rangers... or is it
still Power Rangers (the episodes suggest both ways).

In Power Rangers Turbo... our heroes are coined Turbo Rangers... or is it still
Power Rangers?

In Power Rangers in Space, Bandai suggests they are called Lightstar Rangers, yet the intro to "From Out of Nowhere, Part II" says Andros is a 'Space Ranger.'

for Zeo they are designated individually as Zeo Rangers except for Trey/Jason since Tommy is referred to as Zeo Ranger V when he goes missing but in Wild Force he's referred to as the Red Zeo Ranger

Which brings me to Power Rangers: Lost Galaxy... Power Rangers or Galaxy Rangers? Anyone with thoughts or suggestions

it would make more sense going with Galaxy BUT... sense and Power Rangers are two things that don't go together since Lightspeed refers to them as the Lost Galaxy Rangers.