Super Catchy Anime Songs?

What's the catchiest song from an anime OST that you've heard?

This one's taken the cake for me. It's so catchy and cute waaaaa

RWBY a great.

Also:

Just realized you said anime OST, so...

＼(・ω・＼)SAN値!(／・ω・)／ピンチ! ＼(・ω・＼)SAN値!(／・ω・)／ピンチ!

mis wrote

RWBY a great.

Also:

Just realized you said anime OST, so...

＼(・ω・＼)SAN値!(／・ω・)／ピンチ! ＼(・ω・＼)SAN値!(／・ω・)／ピンチ!

So catchy waaa~
also RWBY took my anime virginity