Final Fantasy
Metal Gear
Breath of Fire
Suikoden
Chrono (yes its only two games and visual novel but smurf you)
Dragon Quest
Seiken Denetsu
Persona
Shin Megami Tensei
Dance Dance Revolution (suck it you couch potatoes )
Legend of Zelda
Sly Cooper
Street Fighter
Guilty Gear

Oddly enough, though I like quite a few series, my favorite games tend to be standalone titles like Vagrant Story and Xenogears. Though I think with enough deliberation I have concluded that MGS3 might be my favorite game of all time.