Sonic the Hedgehog is my favourite Sonic game hands down. It has the most interesting development, the most charming sprite work, and the purest Sonic gameplay (rolling for life). I grant you that this is not a popular opinion, but it (and Sonic CD) is leagues above everything that came after it, to my mind. I also don’t believe all the levels were rushed after Green Hill Zone. It has a specific structure and it really works for me.