I don't know why I care what ParaTed2k thinks of John Lennon's music. I should just feel sorry for you, that this wealth of wonderful pop music is unavailable to you. But I feel compelled to point out that Paul McCartney, and not John Lennon, wrote "The Yellow Submarine" and "The Fool on the Hill". So using them to somehow prove that John Lennon was an idiot does a better job of making you look like one.
As for "I Am the Walrus," the lyrics are deliberate nonsense. I assume you would disqualify the nonsense poetry of Lewis Carroll from the category of genius as well.
And then there's the line from "She Loves You," which admittedly looks pretty unimpressive on the page. But let's remind ourselves that a song does not exist on the page. It is an art work of SOUND. And "She Loves You" is one of the most joyous pop songs ever to come out of a radio. It's also one of the first rock and roll songs about a relationship from the point of view of a third party. It's one of the first rock and roll songs to begin with the chorus, rather than the first verse, which is one of the reasons it's so infectious. And it's the first rock song ever to end on a sixth chord. All this, and The Beatles were still ostensibly a teenybopper band at the time they recorded it.
I just had to get that out of my system.
As for anyone who thinks that Yoko Ono's music is "painfully awful" (and I'm looking in your direction here Jamie), I would direct you to the second track on her first real album Plastic Ono Band, a song called "Why Not." To appreciate her music, you have to give up on convetional ideas of what a singer should do with her voice. Yoko Ono does not sing. She uses her voice like a saxophone: squeeling and squawking and soaring and grunting. The result, to my ears at least, and particularly on that song, is otherworldly, sexy, and funky as hell.
As for the whole "Yoko broke up the band" argument, I direct you to Nancy's post above, which proves she should also be considered a genius (it helps that she's my wife.)