I really can't get Can't Help But Wait - Trey Songz out of my head atm, to the point where it's becoming really irritating. 
same but wen u listen 2 it 2 many times it gets so annoying but the song that i can't get out of my head is SHAGGY FT AKON what's love
Exactly. You know every lyric off by heart and that's, frankly, pretty damn sad.

I love any songs by Akon ! Shaggy is good too, but I don't think I've heard that song.
Also, This Boy's Fire - Santana ft J-Lo is *so* catchy, it's been in my head on and off for a few days.