Kamen Rider Decade. I loved the concept of transform into other Kamen Rider from the past, but the problem is that TOEI couldn't bring the past of KR actors back for the special anniversary!
At least, they did the right thing with Kamen Rider Hibiki actors (except actor of Hibiki) and Kamen Rider Black and RX.
I actually enjoyed Black/RX world, Hibiki World and Shinkenger World. The rest of them... crap. AU is bullshit.
I would like to add some more.....
Go-Onger - I'm telling you... I know most of you guys, who loved/liked Go-Onger, got sick of the Go-Onger bashing. I really hated (and still) this show because it was way too much. The cast sucked. The villains sucked, too. Too much comedy crapfest and idiots. It was really painful to watch. Also, the Go-On Wings were so boring. I expected to see them being completely a badass, but they weren't at all.
Boukenger - I didn't like this show and it was SO incredibly BORING! The cast sucked and the villains were so boring. When I first saw Eiji and he was badass... until he became to BoukenSilver, he was boring, too.
Gaoranger - I managed to watch the whole 51 episodes and I never really care about the hundred power animals. It was completely overkill. Also, this show was boring. I wish there was a main villain instead of only four generals themselves. So disappointed with this. There is only one thing I liked.... Gaoranger VS Super Sentai. I actually liked the special team-up.
Justiriser - I had a hard time to watch this. I thought it was incredibly boring.
Sazer X - Same as Justiriser.
Kamen Rider OOO - Please don't flame me. This show turned me off. I never really care about the actor who played as Ankh. Just like he was in Sazer X. Also, Kamen Rider OOO's multiple form gave me headache. Too confusing. Way, way overkill. That is why this show turned me off. It's just eh.
That's all I have now... I think.