Sorry to be flippant but really, its your choice, they're all good. I have most all of those focal lengths and personal preference has me using some more than others, and I even have 3-4 types of 35's and 50's. Good thing is most will hold their value so buy and try and sell what you find unfavorable. That's all part of the fun.

Basic advice though will be to get a 35/50/90 set, or 28/50, or 35/75, or 35/90, etc....