CyanogenMod
www.cyanogenmod.org/ (HTML5)
CyanogenMod, the oldest and most popular community built alternative Android distribution has a new responsive website. It's now easier than even to learn about and contribute to Cyanogenmod directly from your smart (or not so smart) phone.
The new design, created by Glitch Agency draws design cues from the Android Holo Light theme. It looks good and adapts to virtually every browser from the Opera Mini and Nokia Xpress proxy browser to all modern smartphone, tablet and desktop browsers.
With this redesign most of the cyanogenmod.site is has a mobile friendly design. The main page and blog use the new design, the Invision IP.Board based forum serves a mobile friendly template to mobile browsers. Only the Wiki makes no concessions to mobile support, although it's easy enough to use in mobile browsers.
For more about the redesign, see this Cyanogenmod Blog post.