Originally posted by NaClH2O For your macro, I'd go with the Tamron 90mm f2.8. Great macro lens, also a good short telephoto and a good portrait lens.
I'd get the Pentax DA 50-200 as a telephoto zoom and if you can find one, an FA 50mm 1.4, if you can't find a new FA 50 1.4 you can sometimes find an A 50 1.4 or 1.7 second hand at KEH or eek bay. You will lose the autofocus capability but still have automatic aperture.
I would actually get the 18-55. It is a very good lens for the money. Much better than the usual run of "kit" lenses. If you really don't want to go with the kit, get the Pentax DA 16-45. That will cover the wider end for you until you find out what your favorite focal lenghts are.
NaCl(the Tamron 90 and the FA 50 are my two most favorite lenses)H2O
i have the sigma 18-125 appr. 22-190 in 35mm terms). this lens is very well reputed and it delivered some very fine results..... yet, i'm unhappy since this autumn when i used this otherwise perfect everyday lens (when you want only one lens to carry around) as there is severe pincushoning at the wide end when the motif is near. for documentation purposes i took pictures of a couple of billboards and found this effect on each one of them. i can imagine that the 18-200 will behave similarily. the pentax 18-55mm ("kit") lens doesn't show this effect, so i switched. the sigma 18-125 is otherwise very good also at 18mm for landscapes.
if you can afford it (in the U.S. you have rebates we europeans never get...), try the pentax 16-45mm/f4.0, its one of the best"standard" lenses.