Google Fonts - Making the web more beautiful, fast, and open through great typography
@font-face Generator - Convert font to cross-browser webfont for CSS @font-face use. Allow char subsetting
Font Squirrel - Font Squirrel scours the internet in search of FREE, highest-quality, designer-friendly, commercial-use fonts and presents them for easy downloading. We don't have the most, but we do have the best.
Adobe Edge Web Fonts - Edge Web Fonts is a free service that provides access to a large library of fonts for your web site.
Fontspace - Free downloads of 70,000+ legally licensed fonts that are perfect for your design projects. The best place in the universe to search for amazing fonts.
Fontello - Tool to build custom fonts with icons.