Landscapes, I prefer lenses with no rotation, no extending.
Like 17_40L and 70_200F4L. It is easy to work with slide-in filters on them.
They are not so heavy, I don't need monster tripod for them.
17_40 will do the street. I use 28 3.5 Oly MF for candids. Costs times and times less compare to Sigma 30 1.4, which is nice to have.
If you want to have straight lines for city pictures - you'll need T&S wide lens.
I myself prefer lenses that don't extend. Easier to keep them from hitting anything and also easier to clean them. I don't have 17-40L but the double extension of 15-85 annoy the heck out of me.