There are actually many cover versions better than the original. The thing is, in cases where the cover version is much better, people just don’t know the originals.
Consider who wrote the originals for these cover versions:
Eric Clapton — Cocaine
Joan Jett — I Love Rock and Roll
The Animals — House of the Rising Son
Blondie — Hanging on the Telephone
Soft Cell — Tainted Love
Cream — Crossroads
Led Zeppelin — You Shook Me
Elvis Presley — Hound Dog
Dusty Springfield — Spooky
Okay maybe Respect beats all of those.