You might want to look into Lunar Silver Star Harmony, if you play it digitally it wont have loading times. It was the first lunar game that I have ever played and I didnt come disappointed. The game is fairly short for an rpg(20 hours), the pacing of the story is outstanding, it's an overall classic. I prefer the music & graphics and dialogue of this version over the ps1 release. The only thing ps1 ver has going for it is longer dungeons and some difficulty(which are not important for me in a game such as lunar which is all about the characters, story and setting)
Ys seven is my favourite psp game so far.. It's really outstanding. I prefer it over oath tbh. I prefer the combat system, I love how you can switch between characters on the fly and how you have so many skills to use. Not to mention that the soundtrack is just as good if not better than oath.
In terms of story, I dont really know which I prefer tbh, but Ys seven left a greater impact in my memory atleast.
If you love final fantasy 7, crisis core is an obvious game to play. It's an excellent prequel with a really good story and fun combat.