Originally posted by SylBer ... landscape, go for the DA 15 ltd;
Interestingly, when I am playing Ansel Adams with my 4x5, I tend to use the 210mm focal length more than any other.
Unfortunately, there are no real hard and fast rules about which lens is best for which subject.
A wide angle lens get's pretty tired pretty quickly if it's all you use for landscape photography.
I have always maintained that the best all round lens is the standard lens. On an APS-C DSLR, this translates to somewhere around 30mm. I shot for many, many years using just a 50mm lens on the 35mm format, and I still find myself most comfortable with lenses around the normal range.