Which ring looks the best?

I want to propose to my girlfriend and I don’t know which to get. She’s a very simple girl, and we have talked about rings, neither of us want anything extravagant, and she wants something really simple, and absolutely no diamonds.
She has bigger hands, so I know if I get something tiny it will be hardly noticeable. Help!

sapphires:
http://tinypic.com/r/amsaco/6
http://tinypic.com/r/a14thc/6
ruby:
http://tinypic.com/r/2wqa1jb/6
topaz:
http://tinypic.com/r/xn95op/6
amethyst:
http://tinypic.com/r/dq3mkk/6