There are thousands of beautifully designed free WordPress themes floating around today. While it is usually worth it to head over to ThemeForest and spring for a premium theme for your more popular sites, these free themes can be a great asset when ramping up experimental blogs.
A beautiful theme designed by dynamicwp.net, Fungus has a clean grey and blue color scheme with vibrant colors for the elements.
A dark styled theme from the popular Press75 designers. One of the more unique features of Side Blog is that it uses post thumbnails in the sidebar as well as the main content area.
A somewhat magazine-styled theme by FabThemes.com.
A very minimalist theme, Melville includes no widgets or other bells and whistles. Ideal for writers.
Another minimalist theme, Min adds a couple of features such as a widgetized footer and featured images on posts.
A simple but interesting theme, Ari features two color styles with light and dark backgrounds.
Another very minimalist theme with no sidebars or other widgets. Does include a top menu.
One of the most impressive free WordPress themes available today, Platform is jam packed with features and customization options.
A clean white and light blue theme based on the NattyWP framework.
A very high quality premium-style theme in the personal blog style.
A free WordPress theme released by Site5 web hosting.
Another free WordPress theme released by Site5 web hosting.
A true classic by the well known WooThemes, Canvas is known for its wide array of customization options.
A beautiful design by FabThemes. Zylyz is intended for food/recipe blogs but can be used for anything.
Another magazine theme by FabThemes.