Asteroid is a free responsive WordPress theme. It looks clean, simple and can be customized as it has several widget areas. You can easily add your ads and banners in those places.
Features:
Simple and clean design.
Two-column layout. Option for Full Page.
Widget-supported Sidebar and Footer.
Responsive layout for mobile devices.
Additional Widgetized areas.
Options for inputting scripts and tracking codes.
Custom CSS Option.