What's the best ever written poem in English?

Question:

What's the best ever written poem in English?

please don't be extended in your answers

Best Answer - Chosen by Asker:

It's kind of a sad question, really. This question seems very limiting in its nature. I can think of several dozens of poems that I could list here, but I really think it would depend on the day and the mood as to which one I would list as better than the others. And my list keeps growing.

It's sort of like asking what was the best painting ever painted.