Ok I have officially finished Persona 4 Golden for real this time (I played it on my Vita when in middle school but I wasn't using a guide + don't like Marie so I missed like half the game whoops). I have yet to play Persona 3, but here are the u/jamiebond official breakdown for my own personal opinion on the Persona games.

Story: P4 > P5

Characters: P4 = P5 (It's like asking me which child I prefer.)

Virtually everything else (gameplay, music, style, dungeons, etc): P4 <<< P5.

Both equally fantastic games, mind you. But overall Atlus clearly learned a ton (probably got way more funding and staff too I'd imagine) and it definitely shows when you compare P4 and P5. However, I'd still consider the story of P4 superior.