My pick is Sonic & knuckels. well it is Sonic 3 & knuckles becuase I play it all the time and I can get Hyper Sonic in that game.

sonic 2 had better levels but i loved the save feature on sonic 3

SONIC 3!!!!!!!!!

Sonic 1 was the best introduction game in the world.
Sonic 2 had the best levels and compatability (including the use of tails)which is why it's my choice.
Sonic 3 was great with the save feature, however one act was rather annoying (the circus) a lot of you who got there will know exactly what i mean
Sonic & Knuckles hgad the best feature, the use of previous games to be combined with previous games.
SEGA/Team Sonic had thought of it all back in the golden days...