Sonic 2, my friend had a MEGA DRIVE so I'd go there and play it pretty often. I always got stuck on Chemical Plant, because I couldn't backtrack a loop. Back then the levels were pretty confusing, so many places to go! Then my friend bought a Playstation and sold his Mega Drive.
Sonic Heroes, I saw it in a store and was like "aw yeah sawnik" The game looked like Sonic 2, very colorful and stuff. I've never 100% Heroes, but I still have the timer maxed out, over 100 hours easily. The most I've spent on a single video game ever.
Sonic 3, Soon after Heroes I started to notice all this Sonic stuff around me, like Sonic Mega Collection, I was so excited to play Sonic 2 again. I remember the first time I beat Sonic 2. The glorious ending music. Anyway, I was spoiled by Sonic 2, so it was hard for me to get into Sonic 1, so I started playing Sonic 3. I was amazed at the save feature. I had a wonderful time... Then I looked up on Gamefaqs on how to unlock more games, and I unlocked Ristar! Now that is a fantastic game!