Marianne Faithfull
Marianne Faithfull was a rocker in her own right before she met her boyfriend, Mick Jagger. The famous arm candy wasn't necessarily a bad thing, though. She was one of the top female performers of her time, though she reflected a darker side of the hippie movement, due to her issues with substance abuse.
Keith Richards
The other half of the Rolling Stones, Keith Richards, was responsible for creating those intricate guitar tones that are prominent in Stones' songs. He and Jagger were just two young kids out on the road together when they first got their start. The band still plays today, and they're still as close as ever.