Some of my favorites (so many are Irish!)

The Fields of Athenry
http://www.youtube.com/watch?v=wJG3mHp8lAs

The Blackbird of Sweet Avondale
http://www.youtube.com/watch?v=TzW-mmMlJ30

The last verse always gets me: "Oh, Heaven, give ear to my consultation
And strengthen the bold sons of Old Granuaile
And God grant that my country will soon be a nation
And bring back the Blackbird to sweet Avondale"

Free and Green
http://www.youtube.com/watch?v=CB_GDoWGDJk

"... and tell them Captain Taggart is coming home tonight..."

The Chill Eastern Winds (Silly Wizard)
I couldn't find an online version - here's lyrics:
"Prepare you sweet flowers, for winter advances
And drink well the sunlight that touches your form.
Draw strength from the earth and repay her with beauty,
For the dark days are comin', oh, and they'll do you harm.

When the chill eastern winds replace summer breezes,
And the long summer days are remembered no more,
Then you'll know how it feels when a woman's love changes,
When at last she has told you she loves you no more.

I saw her today, when she walked with her new love,
In all the fine places that we'd walked before.
They kissed by the rocks where she told me she loved me,
And soon she'll be using those same words once more.

There's none that could blame me for wanting her beauty,
But it lies like a snowflake in the hands of a child.
When the warmth of my love tried to reach out and hold her,
It's then she was gone, to prove she's still wild."

Along the same lines is Richard Thompson's "Beeswing"
http://www.youtube.com/watch?v=HApy-Xoix-g

The Last Trip Home (Ed Miller)
http://www.youtube.com/watch?v=A3mirhMh2ng