For day-to-day use, I prefer the 50mm f/1.8 for my 35mm and FX cameras, and either that or the 35mm f/1.8 DX lens for my DX cameras. I move a few steps to frame my photo, and Voilà, perfect pictures. I carry these small lenses when I'm spending more time carrying my camera than using it.
For people who want to carry just one lens, and don't mind the extra weight, slower speed and much higher cost, the lenses I often use when I'm out on a serious photo trips are:
Nikon 18-200mm VR II DX (72mm filters, 19.9oz/565g, about $850).
For DX cameras, Nikon's 18-200mm VR II has been the top do-it-all lens since it came out in 2005. Except for low-light action or crazy-wide angles, the 18-200mm does everything I need in DX. It covers every reasonable focal length, has vibration-reduction so you can forget the tripod, and you can get instant manual-focus override just by flipping the focus ring.Today's -II version is the same as the original, with a zoom lock at 18mm I never use anyway.
Nikon 28-300mm VR (77mm filters, 28.1 oz./796g, about $940).
For FX and 35mm cameras, Nikon's 28-300mm VR does everything except for action in low-light or crazy-wide angles. The 28-300 also covers every reasonable focal length, has vibration-reduction so you can forget the tripod, and you can get instant manual-focus override just by flipping the focus ring. It is about 25% bigger in every dimension from the 18-200mm; I'm showing them at the same size for detail. With the 28-300mm VR, I can dump all my other lenses into the lake; the 28-300 is perfect for 99% of what I do on serious photo outings. The tiny 50mm f/1.8 is what I prefer to carry day-to-day, and the 28-300 is the ticket for serious all-day shooting.