Simple, minimal designs that focus on making your posts as readable as possible. Try one of these WordPress themes:
The Scherzo theme
Theme page / Live demo / download

The Scherzo Theme
The FON theme
Theme page / Live demo / download

The FON theme for WordPress
133 theme
Theme page / Live demo / download

The 133 theme
Also try
- The Gigantic theme
- The Velouria theme (please bear in mind this hasn’t been updated for a while!)