You have gotten some very good recommendations here. But you didn't really indicate a budget so I am going to toss this out there...
I have used several monopods, including the recommended Bogen unit. They were fine. But last year I decided to move to a Carbon Fiber unit for numerous reasons.
I ended up with the Induro CM-34. I have used that monopod with up to my D3s and 600/F4 and it's as solid as a rock. At around $150, it's a terrific bargain too.
I am going to recommend you avoid quick release anything. Believe me, its a GREAT comfort when you've got a $10k piece of glass and a $5k body on top of a stick and you KNOW the only way that's coming off is if you screw it off. The very idea of a quick release with that kind of weight and expense makes me VERY nervous.