One single line of poetry....

The moving finger writes, and having writ moves on.
Nor all your piety and wit, can call it back or cancel out one word of it.
From the Rubaiyat of Omar Khayam translated by Edmund Fitzgerald.

Tread softly because you tread on my dreams
W B Yeats 'He wishes for the Cloths of Heaven'

The bedroom won’t even look at me
Since you left it, it keeps its eyes closed
All it wants to do is sleep
Remembering better times
Trying to lose itself in dreams
It seems like it’s taken the easy way out
But at night
I hear the pillows weeping into the sheets.

Henry Normal
The house is not the same since you left

Yes, more than a line, but since there is little punctuation in this poem, I'm claiming this as a single sentence

but the grass will be greener wherever you tend to it...

It's a verse rather than a line but:

We have tested and tasted too much, lover-
Through a chink too wide there comes in no wonder.
But here in the Advent-darkened room
Where the dry black bread and the sugarless tea
Of penance will charm back the luxury
Of a child's soul, we'll return to Doom
the knowledge we stole but could not use.

Patrick Kavanagh

I have spread my dreams under your feet
Tread softly for you tread on my dreams

WB Yeats

Time hates Love, wants Love poor,
But Love spins gold, gold, gold from straw (Carol Ann Duffy)

But glad to have sat under
Thunder and rain with you
And grateful too
For sunlight on the garden (Louis Macneice)

She left the web, she left the loom
She made three paces through the room (Tennyson)

Out of the ash
I rise with my red hair
And I eat men like air (Plath)

As kingfishers catch fire, dragonflies draw flame (Hopkins)

But the old man would not so, but slew his son,
And half the seed of Europe, one by one (Owen)

Why did he think adding meant increase? To me it was dilution.

From Dockery and Son by Philip Larkin.

It refers to a peer having children and Larkin not wanting them. Struck me as such an interesting view when I read it at 16.

Golden lads and girls all must, as chimney sweepers, come to dust - Cymbeline.

On my office door I have The Cathedral Builders - the last line is 'I bloody did that' which I adore.

Slough

Come friendly bombs and fall on Slough!
It isn't fit for humans now,
There isn't grass to graze a cow.
Swarm over, Death! - John Betjeman

Living quite close to Slough, this pops into my head ever time we drive there.

In fact, I love Mrs Tilscher's Class so much it may possibly be my all time favourite poem. I think it captures that moment as a child when you realise you will grow up..and the anticipation of this.

You could travel up the Blue Nile
with your finger, tracing the route
while Mrs Tilscher chanted the scenery.
Tana. Ethiopia. Khartoum. Aswan.
That for an hour, then a skittle of milk
and the chalky Pyramids rubbed into dust.
A window opened with a long pole.
The laugh of a bell swung by a running child.

This was better than home. Enthralling books.
The classroom glowed like a sweetshop.
Sugar paper. Coloured shapes. Brady and Hindley
faded, like the faint, uneasy smudge of a mistake.
Mrs Tilscher loved you. Some mornings, you found
she’d left a gold star by your name.
The scent of a pencil slowly, carefully, shaved.
A xylophone’s nonsense heard from another form.

Over the Easter term the inky tadpoles changed
from commas into exclamation marks. Three frogs
hopped in the playground, freed by a dunce,
followed by a line of kids, jumping and croaking
away from the lunch queue. A rough boy
told you how you were born. You kicked him, but stared at your parents, appalled, when you got back home.

That feverish July, the air tasted of electricity.
A tangible alarm made you always untidy, hot,
fractious under the heavy, sexy sky. You asked her
how you were born and Mrs Tilscher smiled,
then turned away. Reports were handed out.
You ran through the gates, impatient to be grown,
as the sky split open into a thunderstorm.

This one:

In his dark room he is finally alone
with spools of suffering set out in ordered rows.
The only light is red and softly glows,
as though this were a church and he
a priest preparing to intone a Mass.
Belfast. Beirut. Phnom Penh. All flesh is grass.

I love the rhythm of this poem. I think Carol Ann Duffy writes very atmospherically, I also love 'In Mrs Tilscher's Class' by her.

From T S Elliot's The Wasteland:

I will show you something different from either
Your shadow at morning striding behind you
Or your shadow at evening rising to meet you;
I will show you fear in a handful of dust.

And there's one verse for Carol Anne Duffy's The War Photographer...

Memorable from school:
If you can fill the unforgiving minute
With sixty seconds' worth of distance run,
Yours is the Earth and everything that's in it,
And - which is more - you'll be a Man, my son!

If by Rudyard Kipling

But my favourite poem is "My mistress' eyes are nothing like the sun by Shakespeare.

Sneak home and pray you'll never know
The hell where youth and laughter go

^Sneak home and pray you'll never know
The hell where youth and laughter go.^

Argh. Bloody intnet.

Some day I shall rise and leave my friends
And seek you again through the world’s far ends,
You whom I found so fair
(Touch of your hands and smell of your hair!),
My only god in the days that were.

Rupert Brooke

Some day I shall rise and leave my friends
And seek you again through the world’s far ends,
You whom I found so fair
(Touch of your hands and smell of your hair!),
My only god in the days that were.

Rupert Brooke

Things fall apart; the centre cannot hold;
Mere anarchy is loosed upon the world

The Second Coming, Yeats

and:

This is the way the world ends,
Not with a bang but a whimper

The Hollow Men, T S Eliot.

Gosh, that's depressing. Better also throw in Frost;

The woods are lovely, dark and deep,

But I have promises to keep,

And miles to go before I sleep

'that even the weariest river, winds somewhere safe to sea' (AC Swinbourne)

' Does it come as a surprise, that I dance like I've got diamonds at the meeting of my thighs' (Maya Angelou)

'We could stream through the eye of a needle' (Heaney)

'Sakes, it's only weather' (Robert Frost)

And the night shall be filled with music,
And the cares, that infest the day,
Shall fold their tents, like the Arabs,
And as silently steal away. (Longfellow)

Thanks for starting this thread OP

Wonderful thread. Lots of those on here including the windhover

I thought I saw my late espoused Saint... I waked, she fled, and day brought back my night.
Milton on dreaming of his lately dead wife.

O western wind, when wilt thou blow
That the small rain down can rain?
Christ, that my love were in my arms
And I in my bed again.

In my new de Dion bouton
Came across a pack of trippers
Thought they were a flock of mouton,
Squashed them flat as any kippers.
What a nuisance trippers are.
Now I must repaint the car.

This sceptred isle..

And the cream of all my heart
I will bring Thee.

A box where sweets compacted lie.

Something understood . From prayer by Herbert.

Vides ult alta stet nive candidum Soracte..

Jenny kissed me when we met,
Jumping from the chair she sat in.
Time, you thief , who love to get
Sweets into your book, put that in.
Say I'm weary, say I'm sad,
Say that health and wealth have missed me,
Say I'm growing old, but add
Jenny kissed me.

Leigh Hunt on being greeted by Jane Carlile.

If you no longer live,
if you, beloved, my love,
if you have died,
all the leaves will fall in my breast,
it will rain on my soul night and day,
the snow will burn my heart,
I shall walk with frost and fire and death and snow,
my feet will want to walk to where you are sleeping, but
I shall stay alive,
because above all things
you wanted me indomitable,
and, my love, because you know that I am not only a man
but all mankind.

The Dead Woman - Pablo Neruda

And yet I can't cure myself of love
For what I thought you were before I knew you.

Defining the Problem, Wendy Cope

A couple already mentioned here:
My absolute favourite:
I was much too far out all of my life
and not waving but drowning'
Like others have said this has always resonated with me... Haunting!

And, 'dulce et decorum est
Pro patria mori'
From GCSE - never forgotten it!

But here's one no one mentioned (and is a bit more cheery)! Comes from a poem called The Promise by Eileen Rafters and we had it read at our wedding:
'i promise, to weave your dreams into my own.
That wherever you breathe shall be my heart's home'