I used the 80, 50 and 150 and found I used them all nearly equally - the 150 for portraits, the 50 for architecture, landscapes and some environmental portraits and the 80 for full body portraits. There are some wonderful deals on some of this stuff currently.
I still can't believe that I sold my Hasselblad stuff to finance a D1x about 8 years ago. The D1x is sitting unused in a bag. That never happened with the Hasselblad.