Shin Megami Tensei peaked in 2009, with the release of the games Devil Survivor and Strange Journey on the Nintendo DS (and optionally Persona 3 Portable on the PSP if you swing that way). The series has not peaked since, and it peaking there is not a good thing because there's still more to have explored, and it will never peak again because they misplaced all of the good writers.

Difficulties:
Easy: 4.5
Normal: 6.5
Hard: 8
Extreme: 10