One thing I have I’ve learned in photography is to always carry a zoom lens. If you shoot photos for fun or you get paid for making photographs, you will find need for a zoom lens. There are spots you just can’t reach, things you cannot get close to. A zoom lens will afford you that opportunity. Though my Nikon 35mm F1.8 remains my favorite lens and is almost always on my D90, the Sigma 70-300mm F4-5.6 DG Macro is by my side often now.