We have a seperate topic for that discussion.

http://www.tokunation.com/showthread.php?t=416

Gekisou Sentai Carranger. I stopped watching SS shows for quite a while because of that series. I absolutely loved Chōriki Sentai Ohranger until they started to lighten it's tone. Despite that, I still enjoyed the series quite a bit and it's still in my top 10 SS shows.

I've only seen bits of Shinkenger and through episode 23 of Kyoryuger.

Should I count myself lucky?

I'm also kicking around an idea for a Video Game themed Sentai, where each ranger personifies a genre. May have Blue Starscream Red depending on how things happen. One idea right now is them being able to summon characters from franchises under their genre. It seems to me that my idea can either be epic win or fail.

It is a tie between Go-Buster and Goseiger. Both are extremely boring and bland to watch.

Grey, CarRanger is one of the greatest Sentai series ever!

What's with all the Goseiger hate? Saying Goseiger was bad is just plain wrong, because it wasn't. True, the first half of the show isn't quite a masterpiece, but once the story unfolds, it was actually really good.
And wtf, Goseiger had flad characters? What about Gaoranger, Dekranger, Boukenger, Go-Onger...? Many Sentai have extremely flat characters, but Goseiger doesn't.

To me, the worst one so far is Boukenger. Akashi is the most unlikeable Red I've ever seen, Blue and Pink have almost no character development (as if they forgot about them), there is no actual plot (except for the background stories of Black, Yellow and Silver) and the villains are pretty boring. Also, the finale was the least touching I've ever seen. They fought like in every episode, no epic roll call, no dark sky, no rain, no NOTHING to make this epic.

I haven't watched enough Sentai to say any of them is my worst but I have no interest in Goseiger after the first episode.

Out of the shows I've finished, and tried, my least favourite is Dairanger.

Dairanger isn't bad...exactly, but people act like Dairanger is the second coming when in reality there is barely any characterisation, the pacing is abysmal and the plotting is terrible. It has great fight scenes, the Ranger powers and stuff are cool and everything but with the way sentai was introduced to me, I didn't expect it to tell a worse story, and have worse characters than your average Neo Saban series.

I thought Dairanger had some good characters, mostly Daigo and Kou. The pacing wasn't great but the ending was the worst.

Ahhhh, don't scare me x,D I wanted to watch this one after I finished Den-O....

I don't know any Sentai I hate. Usually I just stop watching when it gets boring so I can't form a fair assessment. I do love all the ones I've finished, though.