No matter how much fun the other characters' quests are there is no denying that Sonic is the star of Sonic the Hedgehog. Sonic levels are long and well thought racetracks - the coins and enemies are merely side dressing to Sonic's incredible speed. The first ten seconds of speed highway say it all; wow. The thing is, just about every Sonic level is impressive in its own way, on top of that each level has many impressive features within it; this is great news for gamers around the world but bad news for a webmaster trying to make a multimedia showcase of Sonic's quest. Anyhow, here are my picks for most impressive levels from Sonic's quest without ruining the suspense of the last level/boss and story line.
Twinkle Park is where Sonic's quest makes a turn from good to amazing; there's just so much going on that it's difficult to take everything in, makes you wish for a replay mode...

Twinkle Park (2:53 Min) - 17.9 Meg MPEG Format
Speed Highway, the one and only... if you haven't seen it in motion yet, prepare to be amazed.

Speed Highway (2:53 Min) - 17.9 Meg MPEG Format
Sonic's run through Dr. Eggman's eggship is a sight to behold; laser cannons shooting at you left at right, wind impeding your progress, and watch out for that sudden elevation!

Eggship (3:15 Min) - 20.3 Meg MPEG Format
Fighting Chaos 6 is a difficult task, half the battle is figuring out what to do since Chaos 6 isn't defeated directly with the stomp move.

Chaos 6 (1:20 Min) - 8.39 Meg MPEG Format
No, Sonic doesn't make an appearance in Jurassic Park, he's just racing through one of the game's last levels. Sonic Team went through a lot of trouble to conduct research for this level, going as far as traveling to excavation sites in the Americas.

Lost World (3:12 Min) - 19.9 Meg MPEG Format