Well, the only one I owned in my younger years was sonic 2.
And if there was a system that could tell you, it would have said that had a like 110% completion of that game. I played the hell out of everything got all the emeralds. If I knew there was a market for it I. Would have started speedrunning it.
Knuckles is my fav character in the series, so obv. S+k was big for me.
Contrary to what some might think, I actually didn't play THAT many sonic games, but it was def. My favorite series.
The adventure series were probably the two best sonic games in the history of the character though. It was probably the one time that sonic was universally better than mario.