My favorite key is G major because I love how the 3rds and 5ths sound. I also really enjoy B major, D major, C major, F major, Bb major, Ab Major, G# minor, Gb Major, F# major, E major, E minor, A minor, G minor, D minor, C Dorian mode, G Dorian mode, and D Dorian mode.
Super stoked to hear more of your arrangements dude. You are seriously underrated! Your talents are inspirational and will spread far and wide. Keep at it!