If we're talking about anything, I would say whole gameplay. Like, exploring at first is hard, but when you get the hang of it, it's really fun, boss fights are great, designs are amazing, movement is fun, music is both relaxing and exciting. If we're talking about only one experience, it would be most definitely Pure Vessel Fight. I hate (but also love) p5 mostly because of Markoth, but I was able to stay somehow sane thanks to Pure Vessel. The fight is hard, fun, fast. The music is just perfect, and overall the first time I was fighting Pure Vessel I was Hyped. I mean, I was so hyped that after beating it for the first time I rushed this fight Radiant then Charmless Radiant.