Classic Sonic games: Sonic 1, Sonic 2, Sonic CD, Sonic 3, Sonic and Knuckles
Also sorta count: Sonic 1 8-bit, Sonic 2 8-bit, Sonic Chaos, Sonic Triple Trouble
SRB2 attempts to replicate the general atmosphere of the classic Sega Genesis Sonic games in 3D. Sonic Adventure and friends are NOT counted in this exercise. While at this point Sonic Adventure is old enough to be considered for such a qualification, it isn't what people mean when they say "classic Sonic", and you shouldn't pretend otherwise.
Also sorta count: Sonic 1 8-bit, Sonic 2 8-bit, Sonic Chaos, Sonic Triple Trouble
SRB2 attempts to replicate the general atmosphere of the classic Sega Genesis Sonic games in 3D. Sonic Adventure and friends are NOT counted in this exercise. While at this point Sonic Adventure is old enough to be considered for such a qualification, it isn't what people mean when they say "classic Sonic", and you shouldn't pretend otherwise.