Toei Tokusatsu Universe + Ultraman

Takes place after King-Ohger: Transformation Lesson.

Takes place after episode 23 of Ohsama Sentai King-Ohger.

Takes place after episode 26 of Ohsama Sentai King-Ohger.

Takes place after Dekaranger with Tombo Ohger.

Takes place after the final episode of Ohsama Sentai King-Ohger.

Takes place after King-Ohger vs. Donbrothers.

Takes place after King-Ohger vs. Kyoryuger and Dekaranger 20th.

Takes place anywhere after episode 2 of Kamen Rider Gotchard.

Takes place after episode 15 of Kamen Rider Gotchard.

Takes place after Gotchard Winter Movie.

Takes place after Gotchard winter movie.

Expanded version of a scene from episode 31 of Kamen Rider Gotchard.

Takes place after episode 43 of Kamen Rider Gotchard.

Takes place after the end of Kamen Rider Gotchard.

Takes place after Graduations.

Prequel web series spinoff of Kamen Rider Gotchard. Spoils the show and is best watched afterwards.

Alt timeline of Gotchard; technically non-canon

Non-canon comedy special featuring Riders from all eras of Kamen Rider

Prequel specials promoting and leading up to Paradise Regained.

Takes place after Superhero Senki due to that being the last appearance of Faiz.

Takes place between episode 21 & 22 of Ultraman Arc.

This is a special episode taking place right before Bun Violet (Homura Sakito)'s introductory arc in episodes 16-18 of the series. I would place it AFTER episode 18 as this somewhat spoils Sakito's backstory. It features cameos from characters from Go-Onger, Kyuranger, Zenkaiger, and Donbrothers.

Part 1 takes place after episode 1 of Bakuage Sentai Boonboomger. Part 2 takes place after episode 7.

Takes place after episode 20 of Bakuage Sentai Boonboomger.

Crossover film with King-Ohger. Takes place following the finale of Bakuage Sentai Boonboomger.

Takes place 30 years following the conclusion of Ninja Sentai Kakuranger.

Gavv Chapter: Takes place between episodes 8 and 9

Valen Chapter: Takes place after episode 14

Vram Chapter: Takes place after episode 20

Alt timeline special. Released after episode 26 and fits fine there.

Takes place after episode 28 of Kamen Rider Gavv; also takes place after Gotchard Graduations and Hopper1's Spring Break. Kamen Rider Gotchard: Final Stage takes place after this.

Takes place after Majade with Girls Remix.

Takes place after episode 44 of Kamen Rider Gavv.

Takes place after Kamen Rider Gavv. Kamen Rider Gavv: Final Stage takes place after this.

takes place after the final episode of Kamen Rider Gavv

a "what-if" scenerio, re-evaluated from Nyelv's perpective, where Rakia had not yet switched to Shoma's side and Nyelv had caught on to Rakia's true goal. Spoiling major events of the series. Best watched afterwards.

A comedy miniseries released after the finale of Kamen Rider Gavv. Optional.

Anniversary epilogue taking place after the finale of Kamen Rider Kuuga and after Kuuga's most recent appearance in Superhero Senki.

Comedy special with anniversary characters from Kamen Rider and Super Sentai discussing Gozyuger's nature as an anniversary series. Optional.

Super Sentai series celebrating the 50th anniversary of the franchise.

These don't really need to fit into continuity, and hence the first episode doesn't. The second does; it can fit any time after episode 6.

These specials are non-canon to the show due to them regularly breaking the fourth wall. If one were to place them in continuity, the earliest they can take place is episode 5 and each proceeding episode takes places after the events of whichever episode the confessional plan is discussing. (There are two for episode 35; episodes 32 and 33 both accompany that episode)

Takes place after episode 26 of Bakuage Sentai Boonboomger.

It's hard to determine timeline placement for this as each episode is split into multiple episodes; as such, it will be placed when it finishes airing.

Takes place any time before episode 7.

The first entry in the PROJECT R.E.D series, replacing Super Sentai in Super Hero Time. This is not a Metal Heroes sequel or reboot but it takes elements and inspiration from the franchise.