Nikon 35mm f/1.8G or Nikon 50mm f/1.8G on a Nikon d3100?

I'm looking into buying a prime lens, but stuck between these two, my D3100 having a DX format sensor, the 50mm becomes a 75mm, that's to long of a lens for the tight situations I work in, your thoughts and recommendation?

The main issue with Dx cameras is that while the "effective" focal length increases, the lens characteristics remain.

With a 35mm lens, as with any wide-angle lens, there's a slight amount of perspective distortion. Even though it is used on a DX camera which effectively gives it a 52mm focal length, the 35mm perspective distortion characteristic remains.

Perspective distortion is not usually an issue, except when shooting portraits, as it will make noses look bigger, and faces look rounder. This is why you never see pros use wide angle lenses for portraiture.

Here is a comparison explaining perspective distortion: http://www.althephoto.com/lenses/35mmprime.php

So it really depends on what you want to use the lens for. I have both 35mm and 50mm lenses on a Nikon D90, and I use the 35mm lens more. But I use a different lens for portraiture, so the perspective distortion in the 35mm lens is no bother.

These two are the same quality. I would get a 35 for getting about a 50 in your camera. The 50 would be good for portraits, but a bit uncomfortable in my opinion