Nikon D3100 - best 70-300mm lens?

Thanks.

The latest AF-S 70-300 mm.

In fact you will have to buy AF-S lenses if you wish to use your D3100 in the auto-focus mode

Nikon's 70-300VR

The Nikkor AF-S 70 - 300mm f/4.5 - 5.6. Only lenses with a built in autofocus motor will autofocus on the D3100 (and the rest of the entry lvel line from nikon, they make the cameras with it until the D90), for Nikon, AF-S.

Link: http://www.amazon.com/...000HJPK2C/

Sigma 70-300mm F4-5.6 APO DG Macro

Best is the AF-S Nikkor 70-300mm f4.5-5.6 VR IF-ED. This is a premium grade lens using better design and materials. It uses an inner focusing (IF) design for faster focusing, and provides you with manual override at any time. Extra-low Dispersion (ED) glass, means that CAs are reduced, a common problem for telezooms of this type.

Second best is probably the Tamron SP 70-300mm f4-5.6 Di VC USD which is uses XLD (similar to ED), with an IF type design. The lens is slightly faster than the Nikon at the short end, but obviously Nikon lenses are generally futureproofed better, as well as being made to a higher quality control standard.