Glad to know there's other fans of it. Though it has to be said, "We'll show that creep the REAL SUPER POWER OF TEAMWORK!" just might be the worst video game line ever.
As a kid born in 89', I can say that Sonic really did have a major presence in the media. He even took up half of that giant screen at Best Buy! (anypony else miss that?) Definitely remember reading the comics in my school's library and watching the cartoon with the voice stylings of Jaleel White.
Of course, the games really were where it was at, and many wonderful memories were made blasting through Sonic 2 at my aunt and uncle's place (sometimes with cousins, one of which owned a SNES). Even at a very young age, I knew the Chemical Plant was a classic for its music, it's purple goo (and blue goo snakes), the steep drop in the second act, that twisted satisfaction I got from watching people drown. Suddenly I'd gone from this lush green paradise to a factory, so now anything was possible. It was glorious. It was Sonic. What a crucial moment it was when I finally got a copy of Sonic Mega Collection Plus and took to my spinball dash again.
Here's the best remix of the theme I've ever heard:
http-~~-//www.youtube.com/watch?v=XXUNyIHH39A
As for Adventure, my best memory with that was playing it at Nickel Nickel on their Dreamcast during someone's party. Fun stuff, that.