I used to own the Sigma 120-300mm f/2.8 DG OS HSM Sports Lens for Nikon F.
I loved the focal lengths that it covered. Extremely useful for my type of photography (especially with a quality 1.4 or 1.7 teleconverter).
None of the larger retailers are selling it new any longer. You can fined good used copies of it for around $2,800 USD.
I liked everything about this Sigma zoom EXCEPT for it's ruggedness. I was on a photo safari to Monument Valley, USA. One night, I set the lens on my hotel bed, and the lens rolled onto the thickly carpeted floor. The lens was a total loss, with multiple optical elements inside of it shattering!! I'm fairly tough on lenses, but I've never had such serious damaged caused by a relatively short drop onto a thick foam pad.