Here's a list of my (not THE, just MY) top 25 favorite a cappella tracks of the last decade (2001-2010).
Apart from the date range and number of songs, I had to lay down a couple of additional ground rules to make this come up anywhere short of impossible:
-- One song per artist. This rule sucked, but it was the only way to knock my list down below 40 or so without calling in sick to work.
-- No songs from artists with whom I'd have a conflict of interest that could compromise my objectivity - tracks from groups I've been in (Fifth Element, Ball in the House, Four Shadow, 7 Days) or for whom I've arranged a significant amount of music (On the Rocks, Divisi, Outspoken, and a handful of others) weren't considered.
The songs aren't ranked; they're listed alphabetically by artist. I'll turn this into a clip page at sometime before long, but I only have so much weekend to work with. :-)
Basix - "Purple Rain"
The Beelzebubs (Tufts) -"All the Love in the World"
Cadence - "The Dry Cleaner From Des Moines"
The Chorallaries (MIT) - "Hot Air Balloon"
The Chordials (Cornell) -"The Moment I Said It"
Club for Five - "Brothers In Arms"
Cluster -"224"
The Duke's Men of Yale - "What a Good Boy"
The Ghost Files - "Never More Will the Wind"
The House Jacks - "Show Your Face"
Hyannis Sound - "I Still Haven't Found What I'm Looking For"
Imogen Heap - "Hide and Seek"
Kid Beyond - "I Shall Be Free"
The Logarhythms (MIT) - "Blower's Daughter"
McLemore Brothers - "On the Edge"
Mosaic feat. Marc Broussard - "Home"
Overboard -"I Saw Her Standing There (reprise)"
The Pitchforks (Duke) - "As You Go"
Rajaton - "Kivinen Tie"
Rescue - "Battle Hymn"
The Rusty Pipes (RPI) - "For the Widows in Paradise..."
The Scattertones (UCLA) - "Brown Eyed Girl"
Sonos - "Come December"
The Swingle Singers - "God Only Knows"
Vox One - "Kind of a 3"