Just sharing my opinion as I do like them, they just don't do it for me however. They do look better than Apple's, thats for sure.
The top one is very slick, but the icon looks better than the app in this case. If the app could look as clean as the icon I would use that one for sure.
The second just screams Vista to me due to the colors chosen, its the same color harmony as the Windows Logo, y'know the one, the actual icon of a windowpane.
The glass effect on the colorful calculator is very clean I must admit. It generally takes a custom approach to get reflections like that, as filters are too uniform and make their use very obvious to other designers. Hats off to the designer's skills.
I have been using the calculator a lot more than I ever have before with my stupid Ipaq or Razr but I have to agree that the skins aren't really doing it for me..... Anything's better than the default, though....