If you have a Nikon camera with a smaller-size APS-C sensor and F mount then the 18-250mm F3.5-6.3 DC Macro OS HSM from Sigma is an incredibly versatile lens that is a real jack-of-all-trades lens you can carry in any situation. With a focal length spanning from a wide-angle 18mm up to a 250 mm telephoto zoom with macro capabilities to boot Sigma's 18-250mm could easily be your camera's first all-in-one lens or a great replacement for several smaller lenses that you're looking to consolidate.