The Cosmopolitan theme by developer "joshuas_79" is a mostly blacked out theme. This theme includes some custom elements that I have not seen in any other theme. In the quick settings panel when a toggle is on it will be lit up around the edges with a soft blue light. The center of the toggle lights up as well. All toggles that are off will be dark out and have a "turned off appearance". The "lit up when on" toggles has to be the neatest effect in this theme. The top of the menu while in the settings has a red background which stands out so you always know where you are in the system. Text and sliders have been themed white as well which stands out great across the dark black backgrounds. Most buttons throughout the theme have a rounded off appearance which looks very clean. This theme is only $1.80 in the Play Store.
This is a theme chooser theme so you will need to be running a custom rom that supports the theme engine. This will work on Cyanogen Mod, AOKP, or Paranoid Android style roms. Grab it at the source link below.
Via Google Play