Hmmm, Context is important.
Zep: They refused to release singles as they wanted their output to be heard in album context, its important to listen to them in that frame set. Diving in for the odd song just makes them sound like rock excess. Personally I love them, but oddly enough with the exception of many of the "classics". Stairway - oh leave it out, bloody hippy drivel. Levee - Great riff, great drum beat and I love the way you can hear bonzo's kick pedal squeak, but god it gets boring.
Have you tried the first album? I get the impression you like brit blues rock and for me that album is one of the pinnacles of the movement.
Beatles : Bloody great before they grew beards.
For me the Beatles are interesting as a band of a time, they were the first really popular Pop songwriting outfit. I can appreciate what they achieved but for pop, they aren't a patch on the the Kinks.