I'll have to count a bit, hold on.
Holy shit, I had no idea I had actually bought this many Sonic-games O.O
1. Sonic the Hedgehog (16 games)
- Genesis: Sonic 1, Sonic 2, Sonic 3, Sonic 3D Blast, Sonic Spinball
- Gamecube: Sonic Adventure DX, Sonic Adventure 2: Battle, Shadow the Hedgehog, Sonic Mega Collection, Sonic Riders
- DS: Sonic Rush, Sonic Rush Adventure
- Wii: Sonic and the Secret Rings, Sonic Unleashed, Sonic and the Black Knight
- X360: Sonic The Hedgehog '06
2. The Legend of Zelda (10 games)
- SNES: The Legend of Zelda: A Link to the Past
- GB: The Legend of Zelda: Link's Awakening, The Legend of Zelda: Oracle of Ages
- N64: The Legend of Zelda: Ocarina of Time
- GBA: The Legend of Zelda: A Link to the Past (GBA)
- GC: The Legend of Zelda: Collector's Edition, The Legend of Zelda: The Wind Waker
- DS: The Legend of Zelda: Phantom Hourglass
- Wii: The Legend of Zelda: Twilight Princess, Link's Crossbow Training
3. Mario [Main series] (8 games)
- SNES: Super Mario All Stars, Super Mario World, Super Mario World 2: Yoshi's Island
- N64: Super Mario 64
- GC: Super Mario Sunshine
- DS: Super Mario 64 DS, New Super Mario Bros.
- Wii: Super Mario Galaxy
4. Mario Kart (5 Games)
- SNES: Super Mario Kart
- GBA: Mario Kart Super Circuit
- N64: Mario Kart 64
- GC: Mario Kart: Double Dash
- DS: Mario Kart DS
- Wii: Mario Kart Wii
And then, on fifth, there's a three-way tie between these guys:
5.1. Metroid (5 Games)
- SNES: Super Metroid
- GBA: Metroid: Zero Mission
- GC: Metroid Prime, Metroid Prime 2: Echoes
- Wii: Metroid Prime 3: Corruption
5.2. Pokémon [Main Series] (5 Games)
- GB: Pokémon Red, Pokémon Blue, Pokémon Yellow, Pokémon Silver (Had Gold too, but I seem to have lost it)
- DS: Pokémon Diamond
5.3. Final Fantasy [Main Series] (5 Games)
- PSX: Final Fantasy VII, Final Fantasy VIII, Final Fantasy IX
- PS2: Final Fantasy X, Final Fantasy XII
