Turtles or Rangers?
The Turtles are always in-costume. They don't just go to church on Sundays with their Power Ranger costumes on, just to return to the rest of the week as typical teenagers. No way! These turtles have been transformed and renewed and inorganically growth by the blood and power of the Shredding Secret of the Ooze. These Ninjas have always remained as the original characters AKA original cast minus the many actor transitions. Of course, I am a much bigger Power Ranger fan in all due respect. I even made them their own hour long movie when I was just ten. I have never done much for those dang turtles. I was also disappointed by how dumb those turtles were when they once appeared on an episode of those rangers.
Billy vs Donatello
I would rather be Billy than that purple turtle any day maybe, but still, at the same time, the turtles really are ninjas. Those rangers are like teenage pirates in suites. But those same rangers are only partial rangers only at conversion into their powers. They turn on and off their religion, their identities, and that is why it is so easy to catch a ranger off guard at night when their cape is on the rack waiting to dry. Rangers are partial posers. Turtles are more hard core.