I wouldn't classify Mienai Chikara as a ballad.. it's an awesome song though, one of my favs. Same thing for Ring, I guess.
I'm too lazy to list, but a few select choices:
- Snow: B'z never did anything like this again and it is completely awesome. The piano, the lyrics, the ending, Tak's guitar in the end, Koshi's unique singing. So good. Also, pretty much every other track on Friends II, amazing and overlooked album.
- Kirei Na Ai Jya Nakutemo: Wish they would do something like this again.
- Boku Ni Wa Kimi Ga Iru: Probably their best ballad of the last decade
- Raging River: Well, it's both a ballad and a rocking epic.. definitely unique, definitely great. Would like to see B'z do more "progressive" stuff like this.
- Home (e version especially): Classic stuff.
- Lady Navigation 7th blues: Awesome.
Anyway, could easily mention more and more.. B'z has loads of good ballads. Heck, my all time top 10 from B'z would probably be more ballads than rockers!