Death Note opening 2, What's up People?! by Maximum the Hormone
Almost all of the One Piece openings
Tokyo Ghoul opening, unravel by TK from Ling tosite sigure (I haven't seen the anime yet but I'm definitely going to watch it!)
Beside One Piece openings, I love Tokyo Ghoul's, DBZ' and Slam Dunk (I sing to this all the time omg), Gekkan Shoujo Nozaki-kun's, and Ao no Exorcist's. These are the ones I don't skip even if watch them on marathon or whatever.
Butter-Fly ~Digimon Adventure
Zankoku Na Tenshi no Thesis ~Neon Genesis Evangelion
Sorario Days ~Gurren Laggan
COLORS ~Code Geass
Trust You Forever ~ G Gundam
Zeta Toki Wo Koete ~ Zeta Gundam
DAN DAN Kokoro Hikareteku ~Dragon Ball GT
FIRE ~Digimon Frontier
OK! ~Pokemon the Original Series (Japanese)
Advanced Adventure ~Pokemon Advanced Generations
Snow Fairy ~Fairy Tail
first opening for sao and ANOHANA OMG IT'S SADDDD. i think lots of people can agree that hetalia's themes (3 now but like 10-14 variants of each) are catchy and cute and stuff
Agreed ! The opening is so catchy and I think it suits the show well. I hum it or whistle it all the time and my friends always as me what the hell I'm singing. (They don't know what anime really is and the only person who does is called a freak for his interests. He's a weeaboo)