Id personally suggest either using Montserrat or Proxima Nova, both are terrific typefaces which suit just about any design. Once integrated, you'll realize how good they actually look.
Montserrat (free through Google Fonts) : https://www.google.com/fonts/specimen/Montserrat
Proxima Nova (paid through TypeKit) : https://typekit.com/fonts/proxima-nova
We are using Roboto, like the google material design guideline suggests. It's the most typical font for material design and already used at http://crypti.me
Check it out: http://www.google.com/design/spec/style/typography.html#typography-typeface
But please check your fonts in the blog section they differ from the rest of the site.
While you are using sans-serif; style on the site, the blog menus are all in serif; fonts.
We will take a look. Thank you.