Both of them are excellent RPGs, and P5 is better than P4G in visual expression.
In terms of music, I personally think that all of them are highly relevant to their respective story backgrounds, but the BGM of P5 is more popular in the popular market.
The plots are different, but the old players I know generally prefer P4(P4G). Both of them are influenced by the background setting, and the plot and rhythm tend to be dark (P5) and bright (P4), which can move the players at the end.
The Exotic Tale of Goddess is a Japanese rpg two-dimensional style game that is loved by many people. Here, players will be able to play different roles and start a great adventure of the human mind, and they will meet many new partners in the adventure.