I am looking for a fast prime in the 28-35mm range
I have shortlisted these options, what would you choose and why?

1. nikkor 35mm f1.8, cheap but the pictures don't come very three dimensional as I'd like.

2. nikkor 28mm f1.8, fx which is gooood, 28mm which is like my ideal lenght, but I've read that has focus shift issues, awesome colour rendition.

3. sigma 35mm f1.4, fx, f1.4 which is my drug, perhaps the focal is a little too close to my existing lenses, lacks weather sealing so it may suck in dust when focusing

4. sigma 18-35mm f1.8, I know, not a prime but definitely a serious contender in terms of image quality. Only drawback is that is an expensive dx lens.

what would you rather buy and why?

my current setup is d80 + 50mm f1.4g + 85mm f1.4d + sigma 17-50 f2.8 os

thanks