Need "a capella" song suggestions

For the last five years, it’s been a tradition at my military unit for me to sing one a capella song at the Christmas dinner. My choices have typically been short simple tunes like I’ll Be Seeing You, The Christmas Song (Chestnuts Roasting on an Open Fire) and last year’s Night and Day. Now with four months to rehearse, I don’t have any particular song in mind and am requesting help. Anyone know of a reasonably challenging a capella song no more than five verses long without repetitious choruses, preferably with a youtube link to a good performance (a clip from De-Lovely proved quite useful in learning Night and Day) and it need not be Christmas- or winter-themed.

Thanks.

Amazing Grace. Yeah, it’s a hymn, but it sounds good a cappella.

Don’t Worry, Be Happy

One of my favorites that IMO is quite pretty a capella is Hark The Herald Angels Sing

Three Kings Bop?

Slightly more grim…The Minstrel Boy?

Minnie Ripperton did pretty well with Lovin’ You. And the best part is everyone will be waiting to see if you’re gonna do the high part

Mmmm Bop.

You’re in the military? Perhaps I might recommend the Horst Wessel song?

I sing this Tom Lehrer song every Christmas: http://www.youtube.com/watch?v=TSlpCBek1_M

I always liked Caravan of Love by The Housemartins.

I’ll be Home for Christmas.

Danny Boy. It’s often performed a capella anyway.

Maybe Up On The Roof?

Billy Joel’s “And so it goes”.

Everything’s Okay in the USA, though you’d probably need to round up a couple friends.

I have no other suggestions since all the other a capella songs I know are in German.

“Yesterday” by Paul McCartney

Well, now we know when to invade Canada.

Try Dave Van Ronk’s Last Call, which was done in an acappella version.

There is (named for the song?) a Cornell University acappella group called “Last Call”.

Carol of the Bells works very well by a men’s chorus. For example, a fragment of it is sung in The Twelve Days of Christmas by Straight No Chaser.

imogen heap - hide and seek

can’t tube at work, but I bet there are some a capella vids.

Hell, you should steal Straight No Chaser’s version of The Twelve Days of Christmas. The segue into Africa is my favorite part, especially “Fiiiiiive golden rings”.