If Youtube videos do not play reload the page, that's a Youtube bug.
Or maybe now, a few years later, it's a new bug ;-)

Jon Hopkins - Vessel (Four Tet Remix)

Delia Derbyshire - Doctor Who Theme (1963)

Immortal Technique - Tell The Truth Feat. Mos Def, Jadakiss & Eminem

Paniq - Masagin

CocoRosie - Lemonade