A very good poet might make you despair and give up writing for envy, but a great poet will inspire you to write more and greater poems. So, this by Yeats:
The trees are in their autumn beauty,
The woodland paths are dry,
Under the October twilight the water
Mirrors a still sky;
Upon the brimming water among the stones
Are nine and fifty swans.
The nineteenth Autumn has come upon me
Since I first made my count;
I saw, before I had well finished,
All suddenly mount
And scatter wheeling in great broken rings
Upon their clamorous wings.
I have looked upon those brilliant creatures,
And now my heart is sore.
All’s changed since I, hearing at twilight,
The first time on this shore,
The bell-beat of their wings above my head,
Trod with a lighter tread.
Unwearied still, lover by lover,
They paddle in the cold,
Companionable streams or climb the air;
Their hearts have not grown old;
Passion or conquest, wander where they will,
Attend upon them still.
But now they drift on the still water
Mysterious, beautiful;
Among what rushes will they build,
By what lake’s edge or pool
Delight men’s eyes, when I awake some day
To find they have flown away?
*Poetic lineages, in which I post great poems from the past, will now be a regular feature of this blog, roughly bi-monthly. Most of the poets I choose will be sufficiently dead to be in the public domain, but some will not. I hope I won’t be stepping on copyright considerations by featuring them!
exiles child 
I like this new feature–and your poem choice. As for copyright issues, it’s been my observation that poets who slap a noisy “All Rights Reserved…Prohibited, yadda-yadda” at the end of every piece tend to write poems you’d never share anyway. The great poetic movements held sharing at their core.
I got such a great response from the William Cullen Bryant poem, followed up by Rupert Brooke, I could see this had to be a regular feature. Plus, I get to read a lot of grand old poetry while ferreting this stuff out! I think you’re right about the copyright issue.