Never had any SEGA consoles, but I have 3 SEGA developed games, and I have played quite a bit of the Genesis Sonic Games (Except Sonic and Knuckles, haven't played that much) and Streets of Rage 2.

I only ever had one Sega game, and that was for the GBA (I'm pretty sure it was a Sega game anyway, though I don't know where the game is at right now, or even what it was called lol).

Game Gear:
1) Sonic 2
2) Surf Ninjas (Probably is 3rd party, but oh well)

Wii:
3) M&S at the Olympics

And that's the end of my short list.

Soon I hope to own Ghost Squad, and the 2 Sonic Rushes. I also can't wait for the Sonic RPG.

MASTER SYSTEM:
Rastan Saga

MEGA DRIVE:
Sonic
Sonic 2
Sonic 3
Sonic and Knuckles
Sonic 3D: Flicky's Island
Sonic Spinball
Robotniks Mean Bean Machine
Phantasy Star II
Phantasy Star III
Ecco the Dolphin
Road Rash
Road Rash 2
Road Rash 3
Columns
Alex Kidd
Lemmings
Flashback
PGA Tour III
Shane Warne's Cricket
Mortal Kombat
Mortal Kombat II
Micro Machines
Desert Strike
Jungle Strike
Urban Strike
Primal Rage
Ariel the Mermaid
Lion King
Zombies Ate My Neighbours
Action Replay
F1
Super Hang-On
Altered Beast
Global Gladiators
Alien 3
Flicky
Klax

MEGA CD:
Sonic CD
Snatcher
Texas Ground Zero
BC Racers
Corpse Killer (32X)
Night Trap (32X)
Dragon's Lair
Tomcat Alley
Mortal Kombat

32X:
Knuckles Chaotix
Doom
Kolibri
NBA Jam

GAME GEAR:
Sonic
Sonic 2
Sonic Chaos
Sonic Triple Trouble
Sonic Blast
Sonic Spinball
Tails' Adventure
Tails Skypatrol
Sonic Labyrinth
Dr Robotniks Mean Bean Machine
Cuthroat Island
Columns
Bart vs the Space Mutants
Batman & Robin
Night of Darkness
Dragon Crystal
Axe Battler
Sonic Drift
Sonic Drift 2
Coca-Cola Kid
Sailor Moon S
Phantasy Star Gaiden
Phantasy Star Adventure
Shining Force Gaiden
Shining Force Gaiden II
Lunar
Gunstar Heroes
Last Bible
Last Bible S
Lion King
Samauri Spirits
Micro Machines
Garfield
Zoop
Power Rangers the Movie
Power Rangers Mighty Morphin
Mortal Kombat
Mortal Kombat II
Psychic World
Wonder Boy
Wonder Boy Revenge of Dracoon
Asterix and Obelisk
Donald Duck
The Smurfs
Ecco the Dolphin
Spiderman
Global Gladiators
Slider
Phantom 2040
Bugs Bunny
Road Runner
Tom and Jerry
Super Monaco Grand Prix
Alien 3
Magic Knight Rayearth
Areal Assault

N-GAGE:

Sonic N


Well there are a lot more but that is all I could think of from memory.

I have like 8 sonic games.

Not that many, because I was more into Nintendo systems at the time :P

Sega Genesis

Columns
Golden Axe
Mortal Kombat
Mortal Kombat II
Mortal Kombat III
Ms. Pac Man
Revenge of Shinobi
Road Rash
Sonic & Knuckles
Sonic the Hedgehog
Sonic the Hegdehog 2
Streets of Rage
Taz: Escape from Mars
WWF Royal Rumble

Xbox 360
Sonic The Hedgehog (No, I did not want this game. It was a present.)

Let's see

All the North American releases for the Saturn -- and about 30 unique imports
Over 100 Genesis games. Over 100 SMS games. Over 100 Game Gear games.
About 150 Dreamcast games.

That's all I can think of.

Mike from Morgantown