I carry three lenses for 4x5: 125mm, 210mm and 300mm. I haven't used the 300mm for quite a while but it's a Nikkor M and weighs very little, so I continue to carry it knowing that as soon as I leave it home I'll see nothing but scenes which demand that lens and no other. Last year I used the 125mm probably twice as often as the 210mm; the year before, probably the other way around.
For 8x10 I carry 420mm and 210mm. Again, last year I probably used the 210mm twice as often as the 420mm; the year before I probably used the 420mm twice as often as the 210mm. However, over the years I have been using shorter focal lengths much more often than I used to, so the wide angle usage is growing.
I photograph mostly landscapes and townscapes, in one way or another. All B&W.