Character dialogue. Sometimes I will replay just to see the other dialogue from characters I didn't use the first time if it's good enough.
'Hopeless' boss battles where you will much later come back and defeat the guy who squashed you like a bug the first time. A real sense of progression, though hopefully he's not easy.
Dr.Susse said:
You find a book called 'dirty magazine' do you want to read it?
Yes
Begin battle with an extremely hard optional boss- Adult Mag! (In Wild Arms 3)
Virginia: It's kind of sad because I end up comparing myself to them...
Clive: Oh dear. I remember reading this kind of material in my days as a student.
More funny character dialogue that you'll read the mag four times just to see. Can't remember the exact lines for everyone but I'm sure Gallows has QUITE the reaction.