I can't choose just one, here are my favorites game series:
Metal Gear Solid, osu!, Okami, Phoenix Wright, Ghost Trick, Golden Sun, Megaman, 999, Professor Layton, Scribblenauts, Rune Factory, The World Ends With You, Castlevania, Boktai, Metroid, Shining Soul, Summon Night, Riviera, Legend of Mana, Valkyrie Profile, Katamari Damacy, Kingdom Hearts, No More Heroes, Pikmin, Super Smash Bros, Resident Evil, The Last Story, The legend of Zelda, Mario.
(little stop for breathing...)
I think these "is" my favorite ones.
Metal Gear Solid, osu!, Okami, Phoenix Wright, Ghost Trick, Golden Sun, Megaman, 999, Professor Layton, Scribblenauts, Rune Factory, The World Ends With You, Castlevania, Boktai, Metroid, Shining Soul, Summon Night, Riviera, Legend of Mana, Valkyrie Profile, Katamari Damacy, Kingdom Hearts, No More Heroes, Pikmin, Super Smash Bros, Resident Evil, The Last Story, The legend of Zelda, Mario.
(little stop for breathing...)
I think these "is" my favorite ones.