I do have a vibrant so I can compare in the same way... but again there's also differences among Vibrant panels. Anyway, my Vibrant is a bit more blue tinted than my Nexus S, and overall the Nexus S display seems nicer. However, as for viewing angle, the Vibrant doesn't distort at all, while the Nexus S changes color slightly, which I think is due to the gorilla glass in the Vibrant and lack of it in the Nexus S.
Your first pictures... I don't know if it's because of your camera's white balance, but the Nexus S is way too green. If anything, the Nexus S should be warmer (redder/yellower) than the Vibrant, which is what I see and was also reported by many reviewers. Also it should have exactly the same sharpness, so I think your display is kind of messed up... exchange if you can.