[Sh Ranger]

I would put the subplots I don't like in 2 categories: Bad Premise and Bad Execution.

Bad Premise:

ZX not getting his own show or movie
Overlords in Agito
Agito's summer movie
Hibiki's summer movie
Hell Bros in Kabuto
Zeronos' memory problem in Den-O
Time Travel in Kiva
Super Hero War
The first 9 episodes and final arc of Gaim
Cinema in Battride War 2
Super Movie War Genesis

Bad Execution:

Kiriko and Ryouko arc in X
Unidentified Lifeform #0 in Kuuga
Mirror World in Ryuki
Armed Saber arc in Hibiki
Decade's "finale"
Tajadol Combo's debut in OOO
Post-finale arc of Wizard
Drive's non-existent cameo in Gaim
Nira arc in Drive
Ghost's summer movie
Kamen Rider Chronicle arc in EX-Aid
Amazons Season 2
Time Travel in Zi-O
Competition arc in Zero One

I can't complain about Double Riders, Skyrider, Super-1, Black (RX), Shin, ZO or Blade until I watch them.

And I can't find much to complain about Faiz, W, Fourze or Build. These shows must be pretty great to have almost nothing bad to think of.