Anime Anime opening and ending themes that don't fit with the show's tone?

[Xdqwerty Xdqwerty]

The best example I can think of rn:

 

[Stingy Perry Stingy Perry]

For me it’s this one

 

[Tonberry]

The best example I can think of rn:

Holy crap that was infinitely more corny than the thumbnail led med to believe.

For me, it's Air Gear

I guess the weird Japanese Linkin Park song sort of fits the street-y inline skate feel somewhat (I kinda dig it actually), but the opening itself doesn't fit Air Gear at all, or at least not the way I remember the manga, which I remember as being super grungy and edgy, with lots of perverted scenes and violent gang conflicts, but I was like 12 when I stole a magazine from a friend because it had some really horny bath chapter in it that was borderline porn, so my memory of it might be warped.
The intro makes it at least LOOK like a happy, bright low-budget shonen rollerblade show.

 

[Heinzu]

The best example I can think of rn:

That's not bad, I like it.

 

[Xdqwerty Xdqwerty]

 

[Tonberry]

Alright, might just commit heresy and get killed by Rageburner for this, but this one really here's the mother of all unfitting theme songs:

Now before you use me as Eclipse fodder, that doesn't make it any less good, though! The intro is just Guts' Tinder profile and the song is great on its own right, I'm a huge Pen Pals fan. Just that it doesn't really fit the tone of the rest of it, particularly not since the rest of the show has Hiarasawa's god-tier soundtrack.

Really? I think it fits pretty well, at least the early parts of HxH.
Maybe it's because the arabic intro has replaced that one in my head, it's SO good.

 

[Xdqwerty Xdqwerty]

I know I this is an ending theme (and thus I changed the thread title) but still

 

[NeonKnights]

 

[SpcDaicon]

Death Parade OP: =D
Death Parade plot: ='(

 

[Ephemera1_]

Ive always found the first OP of Zeta Gundam pretty funny considering what goes on in that series. Particularly the line " I WANNA HAVEEEE A PURE TIIIIIIIIMMMMMEEEEEE EVERYONES A NOBLE MIIIIIINNNNNDDDDD" for a series about war and both sides essentially using child soldiers to lead the frontier

The best example I can think of rn:

Unironically one of my favorite OPs ever.