For many people, Sonic 2 is the best of the OG Sonic games, but for me it's Sonic 3. The graphics are better, the music is more catchy, there are no annoying stages, the special and bonus stages are fun, the stage transitions are a really nice touch to show you the character's journey, etc. It's a game that really encourages exploration instead of the memetic "gotta go fast" and it really shows: even to this day, I keep finding sections on the stages that I haven't seen back then. A must play, but go for the Sonic 3 Complete hack if you want the full experience since it mixes Sonic 3 with its part 2 (Knuckles) and it's completely customizable to make it exactly like it's beta version before Sega splitted the game in half