my favorite is 1 am, i barely hear it as i almost always turn back the clock to 2 or 3 pm when i play nowadays (for convenience sake, shops closing, visibility etc) but it's such a sad fitting song for that hour at night. makes you feel alone.
2am and 4am. I'm starting to hate 8am-9pm music compared to the other animal crossings for some reason. I can to this day hum probably 60% of the music from the older games but this game idk. All the day music seems really annoying and the same-y to me.
I really like 11 pm, 1 am, and 4 am. I think they're all really serene and fitting for the times they're played.
The music for 7 pm is oddly unsettling during the main piano bit for how much happier sounding 6 pm and 8 pm are. The music would fit better later at night
edit: just listened to 3 am, forgot how much I loved it!
I like 4 am, 1 pm, 9 pm, and 8 am. In NA they should have swapped 4 and 3 am because 3 AM is supposedly the "witching hour," and 4 am is, by far, the most unsettling hourly theme. That's what makes it amazing though.
How did I forget 2 am? That might actually be my favorite.
I played during the 6am time period the other day for the first time and I really enjoyed the music. My favorite still has to go to 1am though, with 11pm being another honorable mention.