1 - Sonic 2

2 - Sonic and Knuckles

3 - Sonic 1

4 - Sonic 3

Sonic 2 (Genesis)-1

Sonic & Knuckles (Genesis)-2

Sonic 1 (Genesis)-3

Shadow the Hedgehog (PS2)-4

Sonic Rivals (PSP)-5

oh and i am looking forward to the next gen ones, but not gonna buy them until i read reviews...probably just rent them

1. Sonic 2

2. Sonic 1

3. Sonic 3 and Knuckles

4. Sonic Adventure 2 Battle

5. Sonic Adventure

Honorable mention goes to Sonic and the Secret Rings. I found the game more enjoyable once I unlocked all of Sonic's skills.

1. S & K
2. Sonic 3
3. Sonic 2
4. Sonic 1
5. Sonic Spinball

Hm... How Recently have the stats been updated???

1. Sonic 3/Sonic And Knuckles
2. Sonic 2
3. Sonic Chaos/Triple Trouble
4. Sonic CD
5. Sonic 1 (Master System/Game Gear)

Anything after Advance 1 (which came out after Sonic Adventure2) were very boring besides Advance 3. (Sonic Rush and Rush Adventure were stale. Oh and I can't stand Secret Rings and I still think Unleashed looks like garbage even without the werehog ;p)