I really appreciate John Piper and his teaching. I'm pretty sure I could listen to him preach for a good 3 or 4hrs without tuning out!

Anyhow, Mark Driscoll tells us why he loves John Piper. Which is probably a better insight into the man than I will ever have because he has met him and I am unlikely to ever meet him. Although if you can meet people in heaven, I'll try and track him down and say thanks!

There are 4 reasons given in the above post and here, Driscoll gives a 5th reason.