It's the Vengaboys, I think. And the song is called Venga Bus, as far as I know.
The lyrics are something along the lines of:
The Venga Bus is comin'
And everybody's jumpin'
(And somethin' somethin' somethin')
But please, leave poor Chris alone with it. It's like when you're babysitting and you do something really silly for a little kid whenever they pull on your nose or something and then they just keep doing it and doing it until you get bored of doing said silly thing and eventually stop. It was funny, but it's already getting old, children!