Oh boy. Here we go! In no particular order, since I'm terrible at ranking things I like.

I'm also not counting the original themes (like Let's Go! Kamen Rider!) since I love all of those original themes and feel like they're easy picks.

Ultraman:
-1: Ultraman Geed No Akashi
-2: Ultraman Taro
-3: Ultraman Mebius
-4: Ultraman Nexus "Eiyuu"
-5: Ultraman Ginga No Uta (does this still count?)

Kamen Rider:
-1: Kamen Rider Zi-O Over X Quartzer
-2: (Skyrider) Moero! Kamen Rider
-3: Kamen Rider Agito Count Zero
-4: Kamen Rider Den-O Climax Jump
-5: Kamen Rider Wizard Life is Showtime

Super Sentai:
-1: Tensou Sentai Goseiger
-2: Tokusou Sentai Dekaranger
-3: Bakuage Sentai BoonBoonger
-4: Samurai Sentai Shinkenger
-5: Kikai Sentai Zenkaiger

Honorable Mentions:
-Ultraman Ace
-Ultraman Tiga Take Me Higher
-Ultraman Orb No Inori
-Ultraman X
-Ultraseven
-Ultraman R/B Hands
-Ultraman Blazar Bokura No Spectra
-Kamen Rider Amazon Rider Koko Ni Ari
-Kamen Rider V3
-Kamen Rider WBX Crime in the City
-Kamen Rider Build Be the One
-Kaitou Sentai LupinRanger VS Keisatsu Sentai Patranger
-Chikyuu Sentai Fiveman
-Kyoryu Sentai Jyuranger
-Mashin Sentai Kiramager

Kamen Rider:

1. Alive A Life
2. Climax Jump
3. W Boiled Extreme
4. Journey Through The Decade
5. Excite

Super Sentai

1. Engine Sentai Go-Onger
2. Dengeki Sentai Changeman
3. Luckystar
4. Chodenshi Bioman
5. Choju Sentai Liveman

I think Back-On and Beverly worked great together for Sky's The Limit though.

What.

Cool, we have 2 of the same picks for Sentai top 5!

A great song and a great meme at the same time.

My favorite Showa Sentai OPs!

https://www.youtube.com/watch?v=b3vIB-KOvEs

That's a very funny error on my end. Probably because I switched out Amazon's Opening. Ha ha!

Huh. Guess I'll have to give my list the good ol' 2.0 treatment. :lolol

Kamen Rider
1. Got Boost? (Kamen Rider Gavv)
2. Surprise Drive (Kamen Rider Drive)
3. NEXT LEVEL (Kamen Rider Kabuto)
4. VISIONS (Kamen Rider Zeztz)
5. EXCITE (Kamen Rider Ex-Aid)

Super Sentai
1. Kousoku Sentai Turboranger
2. Mashin Sentai Kiramager
3. Ole! Ohranger (Choriki Sentai Ohranger)
4. Hikari Sentai Maskman
5. Denji Sentai Megaranger

Ultraman
1. Ultra Spiral (Ultra Galaxy Fight: New Generation Heroes)
2. Trigger (Ultraman Trigger)
3. Aoi Kajitsu (Ultraman Nexus)
4. Take Me Higher (Ultraman Tiga)
5. GEED no Akashi (Ultraman Geed)

Metal Heroes
1. Tokusou Exceedraft
2. Tokusou Robo Janperson
3. Jikuu Senshi Spielban
4. Juukou B-Fighter
5. TRUE DREAM (Blue Swat)

Misc.
1. Mach Baron (Super Robot Mach Baron)
2. Asu e no Sakebi ~ Cyber Heart (Dennou Keisatsu Cybercop)
3. chang[e] (WINGMAN)
4. The Life (Tomica Hero Rescue Force)
5. STORY (Tomica Hero Rescue Force)


Yep, sorry Trigger, but Ultra Spiral hits hard :lolol

Huh, didn't expect this thread to be revived lol anyway here's my new list
1. Break the Chain - Kamen Rider Kiva
2. Zenryoku King! - Ohsama Sentai King-Ohger
3. Over Quarter - Kamen Rider ZI-O
4. Anything Goes OOO - Kamen Rider OOOs
5. LiveDevil - Kamen Rider Revice

Haha, totally fair for the Heisei Centric bias. I'm not an active Showa watcher, and I don't keep up weekly with Reiwa. Is half the last really too recent, though? Gotchard was 2023, but the rest in my top 5 are between 2009-2018.

For me, I tend to gravitate more to pop-ish music, or fast-paced rock. Something that feels more akin to something you'd see as the first opening for a long-running shonen show.