I can't do five, basically my favorite games of all-time.
It's really difficult to narrow the scope as so many games are story, leveling up to learn new skills, etc.
Final Fantasy II NA version (FFIV official)
Secret of Mana
Seiken Densetsu 2/Trials of Mana
Final Fantasy VI
Zelda II: The Adventure of Link
Phantasy Star IV
Castlevania: Symphony of the Night
Castlevania: Dawn of Sorrow
Mass Effect 1 and 2
Dragon Age II
Castlevania: LoS
Final Fantasy XIV (storyline is great)
I guess if we're talking series/franchises:
Final Fantasy
Mana
Castlevania
Easily top 3 for me, 4 if Zelda counts.
Last spot(s) are tough because they're a drop in tier:
Phantasy Star and Mass Effect.