Hosanna by Hillsongs United. It has been on my mp3 player since I first heard it, and I listen to it practicaly every time I get in the car.
And thus I pass my obsession onto you, lucky reader.
No really, a great great tune.
"I see a generation
Rising up to take the place
With selfless faith, with selfless faith
I see a new revival
Staring as we pray and seek
We're on our knees, we're on our knees"