Lens for nikon D3100?

I'd like to get a 70-300mm lens, but there's so many different brands! And then there's so many reviews I can't get even down to two different ones. Anyone out there have any recommendations?

Optekas are the way to go

Stick with Nikkor if you can afford it.

Nikon has always made some of the sharpest lenses available.

Example:
http://www.amazon.com/...B000HJPK2C
http://www.amazon.com/...B0041MI3OI

Get a 55-200 VR or 55-300 VR.

For the D3100, Nikon only makes one that will autofocus with your camera, the Nikon 70-300mm AF-S VR. It's fast, quick-focusing, and upward compatible if you go onward to full-frame cameras in the future.
http://bythom.com/70300VRlens.htm
http://www.kenrockwell.com/...300-vr.htm

You can consider 3rd party lenses, but only Nikon lenses are obsolete-proof with future technologies.

That depends on why you'd want one.

The cheapest quality option for your camera is nikon's 55-300