Let's get this anime OP/ED banger list started. First off the best anime OP of all time: Girls und Panzer.
I'll keep the pattern of OP then ED. Best ED of all time once again goes to: Girls und Panzer.
Next we'll go with an absolute classic OP: Mobile Suit Gundam.
Despite the series being mid as fuck the ED absolutely slaps: Fate/Extra Last Encore.
Another old school mecha anime? What a surprise! Next OP is for: GaoGaiGar.
Hard to pick 1 FMA/FMAB OP/ED out of the 18 but Shunkan Sentimental wins for me.
Next OP is: Smile Down the Runway.
The point where the anime actually got good: Sword Art Online Alicization.
More mecha? Always good for the soul: Gundam Build Fighters.
I really vibe with mecha anime music: Gundam Iron-Blooded Orphans.
From the most comfy anime ever made: Yuru Camp.
Possible AOTY for 2020: ID:Invaded.
A very recent mecha OP: Gundam Build Divers Re:Rise.
Another contender for AOTY 2020: In/Spectre.
The anime that seems educational but teaches absolutely fuck-all: Dr. STONE.
I am running out of caption ideas. From the anime with the most possible places on this thread: K-ON!.
From the best Gundam AU: After War Gundam X.