Led Zeppelin is a really good but also really overrated band. (Overrated because of whiny baby-boomers). They are best known for their Pro-Satan power ballad "Stairway to Heaven".
They reunited in 2007 for a one-off show, and are supposedly in talks to for a new album and tour, proving that everybody has their price.
Led Zeppelin, contrary to popular belief, is not a heavy metal band. Led Zeppelin is a proto-metal band.