I tend to like some of the bleaker poems, though I'm not too sure why. The Raven by Edgar Allen Poe is a favourite, as is The Goblin Market by Christina Rosetti (both far too long to quote - The Raven being about 3 pages, and the Goblin Market being a rather whopping 12, though the lines are short. The Divine Comedy by Dante Alighieri is also a fantastic piece of writing, but again, far too long to quote! Dante Rossetti wrote a sonnet sequence called the House of Life which is, I suppose, a collection rather than a single poem, consisting of (I think) 100 poems I'm quite fond of. The Highwayman is also very well done, and Loreena McKennitt did a song version that's pretty good. I have a few favourites as you can see
More quoteable, though, my two favourites are A Poison Tree by William Blake and an unnamed (AFAIK) poem by an unknown poet - it's attributed to a few people, but I don't think anything's certain.
Blake's:
I was angry with my friend:
I told my wrath, my wrath did end.
I was angry with my foe:
I told it not, my wrath did grow.
And I watered it in fears,
Night and morning with my tears;
And I sunned it with my smiles,
And with soft, deceitful wiles.
And it grew both day and night,
'Til it bore an apple bright;
And my foe beheld it shine,
And he knew that it was mine,
And into my garden stole,
When the night had veiled the pole:
In the morning, glad, I see
My foe outstretched beneath the tree.
And the unknown one:
Do not stand at my grave and weep;
I am not there;, I do not sleep
I am a thousand winds that blow
I am the diamond glints on snow
I am the sunlight on ripened grain
I am the gentle autumn rain
When you awaken in the morning's hush
I am the swift, uplifting rush
Of quiet birds in circled flight
I am the soft stars that shine at night
Do not stand at my grave and cry;
I am not there, I did not die
Pete