I was always a Nintendo kid when I was younger, so I didn't get to play too many SEGA games. However, one game I did get plenty of time to play at my friend's house was Sonic The Hedgehog. Sonic Underground is the 3rd animated series to utilize the Sonic The Hedgehog character. Broadcast at the end of August, 1999, the series was preceded by The Adventures of Sonic The Hedgehog, Sonic The Hedgehog and followed by Sonic X in 2003. The little rodent sure did get a lot of cartoon action. Sonic Underground spawned 40 episodes and you can currently find all 40 on a DVD from Shout! Factory.
Sonic Underground Cartoon Intro