GREATEST opening line to a song

Of course you do. And with that said, I offer you the following:

"The bigger the cushion, the sweeter the pushin'
That's what I said
The looser the waistband, the deeper the quicksand
Or, so I've read"

And you my love

Won't you take my hand

We'll go back in time

To that mystic land

Where the dew drops cry

And the cats meow

I will take you there

I will show you how

Collipark, yea.

I don't know if it's the greatest, but Zeppelin's Black Dog is the first one I thought of:

Hey hey mama said the way you move
Gonna make you sweat, gonna make you groove

+1

OP asked for THE GREATEST opening line. You only get one go at this.

If I ventured in the slipstream, between the viaduct of your dream where immobile steal rims crack, and the ditch in the back roads stop, could you find me?

Van Morrison, Astral Weeks

Please allow me to introduce myself I'm a man of wealth and taste

In the time of my confession, in the hour of my deepest need
When the pool of tears beneath my feet flood every newborn seed
There’s a dyin’ voice within me reaching out somewhere
Toiling in the danger and in the morals of despair

Don’t have the inclination to look back on any mistake
Like Cain, I now behold this chain of events that I must break
In the fury of the moment I can see the Master’s hand
In every leaf that trembles, in every grain of sand

Bob Dylan is a freaking genius.

Now you're getting there.

"Starry, starry night .." -- Van Morrison

"Sleep all day, out all night, I know where you're goin'. I don't think that's acting right, you don't think it's showin'." -The James Gang, Funk #49

What sort of commie miscreant gives Johnny Cash a thumbs down? 🤨

NWA-
Straight outta Compton, crazy mother*****r named Ice Cube
From the gang called N*****z With Attitudes
When I'm called off, I got a sawed off
Squeeze the trigger, and bodies are hauled off

Dylan-
Early one morning, the sun was shining
I was laying in bed
Wondering if she'd changed it all
If her hair was still red

Crosby, Stills and Nash-
Got out of town on a boat, going to Southern islands
Sailing a reach before a following sea
She was making for the trades on the outside
And the downhill run to Papeete

The Box Tops/Joe Cocker-
Gimme a ticket for an aeroplane
Ain't got time to take a fast train
Lonely days are gone, I'm a-goin' home
My baby, just a wrote me a letter

Pixies Where is my mind

Ooohhh Stop

Known to turn off Google alarms

A screen door slams, Mary's dress sways

Like a vision she dances across the porch as the radio plays

Roy Orbison singing for the lonely, hey that's me and I want you only

Thunder Road by Bruce Springsteen

"Wop bop a loo bop a lop bom bom! " I don't know what it means, but I believe it's very profound.

What would you think if I sang out of tune?
Would you stand up and walk out on me?

Got a wife and kids in Baltimore, Jack. I went out for a ride, and I never came back.

You got a fast car
I want a ticket to anywhere