If you didn't post this already, I would have had to think another 5 minutes to pick one. Thanks for alleviating the burden of choosing just one.
A few that come to me as "absolutely fucking yeah" are:残酷な天使のテーゼ
/Zankoku na Tenshi no These (Evangelion)プレパレード
/Pre-Parade! (Toradora!)What's Up, People!
(Death Note Season 2)プラチナ
/Platina (Cardcaptor Sakura Season 3)人として軸がぶれている
/Hito toshite jiku-ga bureteiru (Sayonara Zetsubou Sensei Op1) (Couldn't find the actual OP on YT)
Sakura Kiss (Ouran Highschool Host Club)もってけ！セーラー服
/Motteke! Sailor-fuku (Lucky Star)
But I think I will have to nominate this.https://www.youtube.com/watch?v=P2NHwqqaGpU
てさぐれ部活もの/Tesagure! Bukatsumono OP "Stand Up!!!"
I don't even remember much of the main characters and the stories. But this is one sure unforgettable song. And yes, the English subtitle on YT is actually what they're singing.
As for non-meta and non-joke OPs,I'll take this. It's one of my personal "march" songs, something I'd still listen to when I need some energy.https://www.youtube.com/watch?v=rPoyoUikA5I
Arpeggio of Blue Steel Ars Nova OP -- Savior of Song