Which prime lens is sharper for a d7000?

I just ordered the d7000 because I know they're gonna discontinue it soon (a couple years). I'm just looking for a very good sharp prime lens with good (doesn't have to be amazing) build quality. I'm looking at the Nikkor 50mm f/1.8G, Nikkor 35mm f/1.8G, the Sigma 30mm f/1.4 EX DC HSM, or the Sigma 50mm f/1.4 EX DG HSM. I'm aware of the crop factor and am really leaning towards the 30mm or 35mm, but can someone tell me if the 50mm's are sharper or anything else?

When picking a lens for your camera, its focal length is more important and any slight difference in sharpness

It will not really mater how sharp a lens is it if does not cover the field of view you need.

Generally "sharpness" is NOT the consideration when deciding to buy a generic lens or the one made by the camera maker. It is longevity. I have Nikkor lenses that were made in the early 1970's and they still work just fine. Most generic lenses start to lose performance (not sharpness) within ten years.

I second that. Sharpness is important, but any decent prime will be sharp so no worries there. Focus on what you need in terms of focal length and your current budget.

Every lens you listed is good, with one exception. I don't own it but the reviews are so very mixed and that's for the Sigma 30mm f/1.4. I was going to purchase it but too many focusing issues, back focusing, soft images etc.

The Nikon is well reviewed. I own the Sigma 50mm f/1.4 for my Sony Alpha, amazing lens I've taken more shots with it since getting it about 14 months ago than with anything else I own. But the 50mm can be tough to use for group shots and in tight spaces it just becomes worthless. So take that into account. A great portrait lens, great for low light, nice walk around lens if you don't need something too wide. I also own a f/1.8 35mm Sony, same problem, it's a bit wider but in tight spaces it's still not wide enough. The 50mm Sigma is stupid sharp when you step down.

I would buy the 50mm, even on a cropped camera. The 35mm lenses introduce a slight amount of perspective distortion. It is not very severe at 35mm, but it does exist nonetheless.

Here is a webpage showing the differences:

http://www.althephoto.com/lenses/35mmprime.php

Thing is, even with a cropped camera, a 35mm lens is a 35mm lens, and although the "apparent" focal length is near 50mm, the lens still retains it's 35mm distortion characteristics.

I would rather use a 50mm and back up just a bit than use a 35mm; if it is going to be my normal lens. But it just depends on how you see using the lens whether or not it is practical for you to back up a few feet.

And for the D7000, you can use the AF 50mm f/1.8D rather than the G lens. The D lens lacks the internal focus motor, but your D7000 has one, so it will autofocus fine. And it is about 60% of the price of the G lens. At around $120, it is the least expensive/high quality lens you will ever own.