John Lennon was a jerk. Bob Dylan is somebody I've always thought about looking into since I know nothing about him. I'll go with PJ Harvey;)
Bob Dylan vs John Lennon

Lennon had his moments, but Dylan had more gravitas. He's a true poet
And what'll you do now, my blue-eyed son ?
And what'll you do now my darling young one ?
I'm a-goin' back out 'fore the rain starts a-fallin'
I'll walk to the deepths of the deepest black forest
Where the people are a many and their hands are all empty
Where the pellets of poison are flooding their waters
Where the home in the valley meets the damp dirty prison
Where the executioner's face is always well hidden
Where hunger is ugly, where souls are forgotten
Where black is the color, where none is the number
And I'll tell and think it and speak it and breathe it
And reflect it from the mountain so all souls can see it
Then I'll stand on the ocean until I start sinkin'
But I'll know my songs well before I start singin'
And it's a hard, it's a hard, it's a hard, and it's a hard
It's a hard rain's a-gonna fall.

When the rain is blowin' in your face
And the whole world is on your case
I could offer you a warm embrace
To make you feel my love.
When the evening shadows and the stars appear
And there is no one there to dry your tears
I could hold you for a million years
To make you feel my love.
I know you haven't made your mind up yet
But I would never do you wrong
I've known it from the moment that we met
No doubt in my mind where you belong.
I'd go hungry, I'd go black and blue
I'd go crawlin' down the avenue
No, there's nothin' that I wouldn't do
To make you feel my love.
The storms are raging on the rollin' sea
And on the highway of regrets
The winds of change are blowing wild and free
You ain't seen nothin' like me yet.
I could make you happy, make your dreams come true
There's nothing that I would not do
Go to the ends of the Earth for you
To make you feel my love.
Mother, you had me but I never had you
I wanted you, but you didn't want me
Momma don't go, daddy come home.
Imagine theres no heaven,
It's easy if you try
No hell below us
Above us only sky
You may say I'm a dreamer
But I'm not the only one
All you need is love - John Lennon

Dylan!
And there's the intertextuality to anothe amazing song 'Chelsea Hotel' By Leonard Cohen.
"Sara"
When the children were babies and played on the beach
You came up behind me, I saw you go by
You were always so close and still within reach.
Sara, Sara
Whatever made you want to change your mind
Sara, Sara
So easy to look at, so hard to define.
I can still see them playing with their pails in the sand
They run to the water their buckets to fill
I can still see the shells falling out of their hands
As they follow each other back up the hill.
Sara, Sara
Sweet virgin angel, sweet love of my life
Sara, Sara
Radiant jewel, mystical wife.
Sleeping in the woods by a fire in the night
Drinking white rum in a Portugal bar
Them playing leapfrog and hearing about Snow White
You in the marketplace in Savanna-la-Mar.
Sara, Sara
It's all so clear, I could never forget
Sara, Sara
Loving you is the one thing I'll never regret.
I can still hear the sounds of those Methodist bells
I'd taken the cure and had just gotten through
Staying up for day in the Chelsea Hotel
Writing "Sad-Eyed Lady of the Lowlands" for you.
Sara, Sara
Wherever we travel we're never apart
Sara, Sara
Beautiful lady, so dear to my heart.
How did I meet you ? I don't know
A messenger sent me in a tropical storm
You were there in the winter, moonlight on the snow
And on Lily Pond Lane when the weather was warm.
Sara, Sara
Scorpio Sphinx in a calico dress
Sara, Sara
You must forgive me my unworthiness.
Now the beach is deserted except for some kelp
And a piece of an old ship that lies on the shore
You always responded when I needed your help
You gimme a map and a key to your door.
Sara, Sara
Glamorous nymph with an arrow and bow
Sara, Sara
Don't ever leave me, don't ever go.
Imagine vs Mr.Tambourine Man?
Strawberry Fields Forever vs Blowin' in the wind?
I'll go for Lennon, for his superior music and variety.
Dylan: 3
Lennon: 1

Standing on the water, casting your bread
While the eyes of the idol with the iron head are glowing
Distant ships sailing into the mist
You were born with a snake in both of your fists while a hurricane was blowing
Freedom just around the corner for you
But with truth so far off, what good will it do.
Jokerman dance to the nightingale tune
Bird fly high by the light of the moon
Oh, oh, oh, Jokerman.
So swiftly the sun sets in the sky
You rise up and say goodbye to no one
Fools rush in where angels fear to tread
Both of their futures, so full of dread, you don't show one
Shedding off one more layer of skin
Keeping one step ahead of the persecutor within.
Jokerman dance to the nightingale tune
Bird fly high by the light of the moon
Oh, oh, oh, Jokerman.
You're a man of the mountains, you can walk on the clouds
Manipulator of crowds, you're a dream twister
You're going to Sodom and Gomorrah
But what do you care ? Ain't nobody there would want marry your sister
Friend to the martyr, a friend to the woman of shame
You look into the fiery furnace, see the rich man without any name.
Jokerman dance to the nightingale tune
Bird fly high by the light of the moon
Oh, oh, oh, Jokerman.
Well, the Book of Leviticus and Deuteronomy
The law of the jungle and the sea are your only teachers
In the smoke of the twilight on a milk-white steed
Michelangelo indeed could've carved out your features
Resting in the fields, far from the turbulent space
Half asleep near the stars with a small dog licking your face.
Jokerman dance to the nightingale tune
Bird fly high by the light of the moon
Oh, oh, oh, Jokerman.
Well, the rifleman's stalking the sick and the lame
Preacherman seeks the same, who'll get there first is uncertain
Nightsticks and water cannons, tear gas, padlocks
Molotov cocktails and rocks behind every curtain
False-hearted judges dying in the webs that they spin
Only a matter of time 'til the night comes stepping in.
Jokerman dance to the nightingale tune
Bird fly high by the light of the moon
Oh, oh, oh, Jokerman.
It's a shadowy world, skies are slippery gray
A woman just gave birth to a prince today and dressed him in scarlet
He'll put the priest in his pocket, put the blade to the heat
Take the motherless children off the street
And place them at the feet of a harlot
Oh, Jokerman, you know what he wants
Oh, Jokerman, you don't show any response.
Jokerman dance to the nightingale tune
Bird fly high by the light of the moon
Oh, oh, oh, Jokerman.
Who is the greatest songwriter of all time? My vote is a tie, John is God but Bob's lyrics transcend music.
(Because you can only have so many Fischer vs Kasparov threads...)