Sort of old now, but What U Got by Colby O'Donis. Not sure why I like this song so much...
http://www.youtube.com/watch?v=Lbtyif6s9ZA
Also been getting Gangnam Style stuck in my head even more after getting Dance Central 3 for the Xbox and playing the song. Lol, running through the Dance Central dance moves in my head while listening to it XD
http://www.youtube.com/watch?v=9bZkp7q19f0
Also the Owl City & Carly Rae Jepsen song Good Time
http://www.youtube.com/watch?v=H7HmzwI67ec