Sonic X Complete Series contains episodes 1-78 of the anime directed by Hajime Kamegami in standard definition

The Evil Doctor Eggman has gathered the seven Chaos Emeralds for his latest dastardly scheme, but like a bolt from the blue, Sonic the Hedgehog arrives to save the day! Only this time, an accident triggers Chaos Control, Hurling everyone into a different world, a world that looks an awful lot like our own. To get home, Sonic together with Tails, Amy, Knuckles, and all the gang must find the Chaos Emeralds. But he’s not the only one looking for them! Doctor Eggman has come to this world as well, and while the other might just want to return, Eggman sees a new land ripe for making part of his Eggman Empire! The race is on, and when it comes to speed, there’s no way Sonic can lose! Don’t blink and don’t think, because Sonic X is out of this world!

English dub only.