These are my favorites:
Rosalina in the Observatory
Ground Theme (Super Mario World)
Bowser's Keep (Hearing the metal arrangement from the other day makes me want to hear the acoustic version.)
Merry-Go-Round
Frappe Snowland
Bayou Boogie
Forest Interlude
Coo the Owl (This arrangement makes me think of a western movie for some reason, lol & I don't even know why.)
Theme of Onett (Playing this on SNES Switch Online gave me a love for this game.)
A Ghost's Pumpkin Soup ...for Pumpkin Hill (Hunting down Emerald shards was more bearable with this theme.)
Tal Tal Heights
Song of Healing
The Great Sea
The Everlasting Sapling