Buying First time flash for Dslr Nikon D5100?

I want to buy Flash for my camera but I'm not able to decide what kind of flash to buy ($300) Can anyone help?

My Cam: Nikon D 5100

You can get the SB-700 for around $325.

The SB-700 is a great mode, and is only $325.

Here's a Flash Buying Guide - http://www.smashingcamera.com/camera-flash-buying-guide/