Black Windows 8 Theme.
Dark8 Windows 8 Visual Style has black taskbar and aero and even explorer.
IF you need to patch Windows 8 to use themes, here’s the tool “How To Setup Windows 8 Visual Style”.
If you wish to get rid of the ribbon use the provided tool Ribbon Disabler for Windows 8, and to use free Startmenu use this app ViStart” Free Startmenu For Windows 8 With Many Skins.