Nikon DSLR users: What's your favorite lens? Why?

This question is pretty open ended. Just curious. You can name more than one lens if it's a tie.

Okay.

Quite fond of my 50mm, my 16-85 and my 150-500. Low light, versatility and the best birding lens for my budget.

Nikkor 24-70mm f/2.8 for its versatility…

Nikkor 300mm f2.8

We use it on our photo finish camera for night greyhound racing.

Sharpness at the maximum aperture are needed to get a sharp image of a greyhound at full speed.

http://philip-northeast.suite101.com/how-the-photo-finish-system-works-a106182