Hot and Cold - Katy Perry Whenever I hear that on the radio it'll take me hours to get it out of my head... just soooooo catchy...
Kiss You Off - Scissor Sisters Better than Single Ladies being stuck in my head. Although Rusland and Ludmilla Overture was stuck in my head a lot yesterday.
From Madonna's Confessions Tour - 'Confessions'. Not exactly a song, just an interlude thing but I've got the spoken words going around and around my head with the trancey music XD