Google Fonts - Making the web more beautiful, fast, and open through great typography
Fonts.do - Fonts.do is the largest database of premium fonts, with more than 300,000 items
Fonts.com - Fonts.com provides the biggest and best selection of high quality desktop and web fonts. Try, buy and download classics like Helvetica, Univers, Frutiger, Trade Gothic and Avenir along with popular new fonts like Soho and Neo. Find your type!
Typefonts - Typefonts is an online database that enables users to discover, download, and use fonts.
Fontstore - Subscription-based access a growing collection of exclusive fonts
Open Font Library - The mission of the Open Font Library is to promote your freedoms as it relates to the use of type.