FWIW, the Matisyahu song "King Without a Crown" very nearly made my Top 10 Singles of 2005 -- I went with KT Tunstall's "Black Horse and the Cherry Tree" instead, and now I'm wishing I'd held both over for this year, since they're both just now accumulating U.S. radio airplay.
Other top singles of 2006 so far include:
Rihanna, "S.O.S. (Rescue Me)"
Sean Paul, "Temperature"
Mary J. Blige, "Be Without You"
Mary J. Blige and U2, "One"
The Animators, "Buy Buy"
and I'm very anxious to hear the new Rosanne Cash.