I loop stuff on BrawlBox, brstm files, and recently been playing the theme for encountering Red and Blue in Sun/Moon. An updated version of the original Blue encounter in RBY. I love it. Generally I loop Pokemon music, exceptions would be the Super Metroid Theme or the Dragon Ball Super theme, the latter of which I created myself. Also the Mortal Kombat theme, the second version, I haven't found the original in looping brstm form. To specify, the second version was used in Mortal Kombat Annihilation, certainly the best part of that movie.
I was actually looping some music in BrawlBox too, but the wav files already had the loop points in the data so it was just simply me converting it over. Haha. Good stuff.
The music was from Sin & Punishment for N64.
btw i feel this a good time to remind you guys that sea of thieves was made by rare, who also made DKC1-3 and DK64, alongside banjo kazooie and conker's bad fur day