Actually Dave I'd forgotten to mention the good old 50mm. It's the one lens that I wouldn't be without. Some great photographers have used the 50mm exclusively. It's a great general lens but can be a little unflattering for portraits on a full frame or 35mm film camera. It's also a great lens, however, for learning your craft on, as you have to work to make things 'fit' properly. I would have to say that when I was on the wedding circuit, the most popular lens for 35mm format was always 135mm, and 80-200mm lenses were always great for wedding shots. Of course, as you say, you have to take in to account the crop factor of DX cameras. I'm hopeless at maths, so I'll let others work out the equivelent focal length.
