there are a lot and I mean a lot of photos here that are awesome.One thing I see is some have almost a "glass" look to them. how did you do this or is it just the same camera being used?
My vote is for low noise sensors and high contrast lenses. The first time I saw what I think you might be talking about was when I saw images from a 5D. The deep shadows made everything just pop into 3D. For me, noisy shadows and low or unrealistic contrast rob an image of that clear realistic look.
Post a link or two so we can get a specific idea of what you are talking about. 