By the #'s

"#1" - Nelly Nellyville
"1 Thing" - Amerie Touch
"3x5" - John Mayer Room for Squares
"3 A.M." - Matchbox Twenty Yourself or Someone Like You
"Testing 1, 2, 3" - Barenaked Ladies Everything to Everyone
"1, 2, 3, 4 (Sumpin' New)" - Coolio Gangsta's Paradise
"1 2 3 4" - Feist The Reminder
"1, 2, 3, 4" - Plain White T's Big Bad World
"4 Minutes" - Madonna Hard Candy
"Next 5" - Minutes Steven Curtis Chapman Speechless
"Smell the Color 9" - Chris Rice Short Term Memories
"7 Days" - Craig David Born to Do It
"10 Days Late" - Third Eye Blind Blue
"17" - Kings of Leon Only By the Night
"20/20" - The O.C. Supertones Loud and Clear
"21 Guns" - Green Day 21st Century Breakdown
"21 Questions" - 50 Cent Get Rich or Die Tryin'
"25 Or 6 To 4" - Chicago The Heart of Chicago 1967-1998, Vol. 2
"26 Letters" - Ben Glover Mix This: Extreme Music
"27 Jennifers" - Mike Doughty Golden Delicious
"32 Flavors" - Alana Davis Blame It on Me
"40 Days" - Third Day Come Together
"52-50" - O.A.R. Stories of a Stranger
"Route 66" - John Mayer Cars [Soundtrack]
"High of 75" - Relient K MMHMM
"75 Grains of Sand" - Sarah Masen The Simply Xcellent $1.99 New Music Sampler
"99 Red Balloons" - Nena 99 Luftballons
"99.9% Sure (I've Never Been Here Before)" - Brian McComas Brian McComas
"100% (Parracent)" - Jabali Afrika Remember The Past
"360" - Josh Hoge 360
"867-5309 (Jenny)" - Less Than Jake Losers, Kings, and Things We Don't Understand

After looking through many of my songs I discovered that some of them have numbers in the titles, so I went ahead and made a playlist with songs with numbers in their titles. There is no common theme, just #'s. I'm sure the Count von Count from Sesame Street would have loved this playlist!