While you all should have Behold the Lamb of God on repeat this time of year, I've got two AP songs on my playlist that bring tears to my eyes pretty much every time. These videos are great, too.
Holy is the Lord (using footage from the movie "The Life of Abraham," which is very well done.)
And his first official music video, for an amazingly poetic and powerful marriage song, "Dancing in the Minefields." For some reason right now, my favorite part is the backup line "Don't give up. Don't give up. Don't give up on me."