all the BW2 gym themes are good, but I have a soft spot for Clay's
https://www.youtube.com/watch?v=FESg8fe0wQs&t=44sAnd the aqua encounter theme. The gacha did a good rendition of it too. I like that it adds a little salsa.
https://www.youtube.com/watch?v=PPdq9EnlBKk&t=67shttps://www.youtube.com/watch?v=1EFhNX_l5m0&t=40s