The screen door slams, Mary's dress waves

Okay, lotta nominations for best opening lines. Let's get right to it. Judge Smails had apparently played this game with his uncle not long ago, and came up with this:

We started playing "What is the greatest opening lyric to an album of all time," which isn't quite the same as your question, but it's damn close. For my money, Zepplin is the jedi master of this genre: Zep I through Zep IV all start with killer lyrics, especially if you think the essence of rock'n roll is sex: I - In the days of my youth I was told what it means to be a man... (Good Times) II - You need coolin', I'm not foolin', I'm going to send you, back to schoolin;' (Whole Lotta Love) III - We come from the land of the ice and snow, in the midnight sun where the hot springs blow (immigrant song) IV - Hey Hey Momma said the way you move, gonna make you sweat, gonna make you groove (Black Dog) Anyway, to answer your original question, I always liked Fleetwood Mac's Monday Morning: Monday Morning you looked so fine. Friday I got traveling on my mind... And Layla is unforgettable: What'll you do when you get lonely? And no one is waiting by your side? Patience by Guns N' Roses is sweet: Shed a tear cause I'm missing you, I'm still alright to smile... People who like soft rock and don't think rock is all about sex always point to Paul Simon for this type of thing: When I look back on all the crap I learned in high school, it's a wonder I can think at all... My personal favorite is probably unknown to most, the Figgs Big City girl: Big City girl is what you claim to be, behind my back so headily, you say we don't belong amidst your fucking social rhapsody....

Solid nominations all. Speaking of Paul Simon, I like the opening to "I Know What I Know":

She looked me over / And I guess she thought / I was all right / All right in a sort of a limited way / For an off-night

DGT chimes in as well:

I've been working on a cocktail called "Grounds for Divorce" - Elbow, Grounds for Divorce don't fall in love with me yet/ we only recently met/true i'm in love with you but/you might decide i'm a nut/ give me a week or two to/ go absolutely cuckoo - The Magnetic Fields, Absolutely Cuckoo You're obsessed with finding a new brain/but what you need is a new body - Rilo Kiley, Accidental Death If I could swallow the sky and the mountains too/I'd do it/so there'd be nothing to fall on you - Jamie Lidell, All I Wanna Do She was an American girl/raised on promises - Tom Petty & The Hearbreakers, American Girl Have you ever been to american wedding?/Where's the vodka? Where's the marinated herring? - Gogol Bordello, American Wedding Well I thought about the army/Dad said "Son, you're fuckin' high" - Ben Folds Five, Army I've seen you laugh at nothing at all/ I've seen you sadly weeping/the sweetest thing I ever saw/was you asleep and dreaming - The Magnetic Fields, Asleep and Dreaming

Now, I've never claimed to be a music afficianado. I love Springsteen, obviously (this recalls a quote from a friend who attended a concert with me: "I thought he'd know 95% of the lyrics... nope, he knew 100%"). And I like classic rock in general, although I'm hardly an expert on it. I've never heard of half the bands DGT references, but those are some very good lyrics. Perhaps I should broaden my horizons...
Finally, one more nomination:

david bowie's space oddity = "ground control to major tom." ok, maybe not a good lyric, but arguably one of the most memorable opening song lyrics ever.