It's still one of the most beautiful pieces of music I can remember hearing, and I found out what it is today. Vide Cor Meum composed by Patrick Cassidy. It was the only piece by a "living" composer on Warner Classics 2006 compilation '40 Most Beautiful Arias'.
He wrote it for Hannibal. That's right, one of the most incredible pieces of music I have heard (though in all fairness there are a lot of those) was written for Ridley Scott's movie about Hannibal 'the cannibal' Lector. O.o That's not actually where it struck me most though. I remember in a vague sort of way thinking the music was beautiful the first time that I saw Hannibal, but where I really remember the piece from is when Ridley re-used it four years later in Kingdom of Heaven as the piece that plays for the clips of Baldwin's funeral. (I'm not counting that as a spoiler since he was a historical figure and he's frickin' dead.)
I bought it from iTunes. And now I'm going to go listen to it again. ...again.
[Edit: I found a link with it!
Here. YAY!]