Oh man. Great thread! Fun poems, all. As for my own, I'll just go ahead and waffle. The short list includes Milosz's Ars Poetica, frost's Accidentally on Purpose, Borges' The Suicide, Bishop's One Art, Bukowski's Something for the Touts, the Nuns, the Grocery Store Clerks, and You, and Stevens' The Disillusionment of Ten O'Clock. Lately, I've been blown away by Averill Curdy's Song and Error (http://www.poetryfoundation.org/poetrymagazine/poem/236832), which I first heard on poetry foundation.org's poem of the day podcast. Still, I think the top spot must go to Rilke, for this one:

The Man Watching

I can tell by the way the trees beat, after so many dull days, on my worried windowpanes that a storm is coming, and I hear the far-off fields say things I can't bear without a friend, I can't love without a sister

The storm, the shifter of shapes, drives on across the woods and across time, and the world looks as if it had no age: the landscape like a line in the psalm book, is seriousness and weight and eternity.

What we choose to fight is so tiny! What fights us is so great! If only we would let ourselves be dominated as things do by some immense storm, we would become strong too, and not need names.

When we win it's with small things, and the triumph itself makes us small. What is extraordinary and eternal does not want to be bent by us. I mean the Angel who appeared to the wrestlers of the Old Testament: when the wrestler's sinews grew long like metal strings, he felt them under his fingers like chords of deep music.

Whoever was beaten by this Angel (who often simply declined the fight) went away proud and strengthened and great from that harsh hand, that kneaded him as if to change his shape. Winning does not tempt that man. This is how he grows: by being defeated, decisively, by constantly greater beings.