Oh but it is so obvious, the best band in the world, infact the best band you never heard is Frank Zappa and The Mothers! Duhh... ! But Led-Zeppelin is my favorite.
The Moody Blues, Stones, Kinks, Creedence Clearwater Revival, Manfred Mann, The Troggs, . Three Dog Night, Gerry & The Pacemakers
I like Ray Manzarek. this song maybe doesn't showcase him as well as "Light My Fire" or "Riders on the Storm". Cool song though!
Zeppelin has some Heavy songs and could be considered an influence for Heavy Metal but... Compiled a Set List of Softer and/or more downtempo stuff from Zeppelin if you want to check out these tunes. Thank You Tangerine Down By the Seaside That's the Way Hey Hey What Can I do Your Time is Gonna Come Going to California The Rain Song All My Love No Quarter