I've always believed that Power Rangers had a lot of potential but the Japanese roots and the childish tone limited what could be achieved with the concept, and yet I kept watching. And here's my opinion on each season:
Might Morphin Power Rangers: I loved it, the soundtrack was magnificent and it's the reason I'm still interested in the show after all those years. But to me it fell short the moment Tommy started to take charge and Jason left.
Power Rangers Zeo: Utterly trash. I only watched it because of Jason's brief return.
Power Rangers Turbo: Was the beginning of a hiatus of not watching Power Rangers as I realised the direction they wee going and hated it.
Power Rangers In Space, Light Speed, Lost Galaxy, Time Force (I'm not sure of the order) were all sheer nonsense.
Power Rangers Wild Force: It somehow brought me back to my seat, and amazingly Jason made a brief cameo as the original Red Ranger in Forever Red which even glued me to watch more. The season was good but that Snow White wanna-be princess made me wanna barf all the time, all her reactions were fake. And Cole the Red Ranger was a distraction. Merrick on the other hand was a really interesting character, he was the main reason I continued to watch it till the end.
Power Rangers Ninja Storm: In my opinion, the worst power rangers season I've ever watched, i couldnt even stomach watching past the first 10 episodes. nough said.
Power Rangers Dino Thunder: Wow! Tommy was back and the zords were dinosaur themed again. and its soudntrack was amazing. I felt it was the direct sequel to Mighty Morphin and the actors werent really as silly as the previous. but I hated the ending, that they lost their powers.
Power Rangers S.P.D: Lacked the thing I loved about Dino Thunder, but the stories were well built up to and the characters well developed that I couldn't help it but watch it till the end. Shadow Ranger was my favorite, and I loved the ending that opens for continuity.
Power Rangers Mystic Force: The story was solid and with a little Star Wars-like twist. Koragg was a great character. but the actors all sucked in and out of costumes, I found myself longing for Dino Thunder's charisma.
Power Rangers Operation Overdrive: As soon as i heard the opening theme I knew it would suck and it did. BIG TIME. The suits were good though.
Power Rangers Jungle Fury: It was good but didnt appeal to me. Still missed the charisma of Dino Thunder.
Power Rangers R.P.M: Now, that came as a surpise! I watched expecting nothing of interest. I was beginning to frankly stop bothering to watch Power Rangers till they bring back Jason the original Red Ranger in the titles again (still waiting for that to happen actually)... but then as soon as I started watching I was open-mouthed. I t was like watching Power Rangers meets Terminator!!! I loved it!!! By all measures the best Power Rangers show yet. Totally cool and witty. and the Rangers are well portrayed and acted. Can't wait to see how it ends.
I've heard about a rumor that in 2010 they plan on remaking Mighty Morphin Power Rangers again and if that happens I wish they bring back Jason again and keep him as the center of events.
That's all for now.