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 ;-)

Alesso - Tear the Roof Up

Ghastly & Mija ft. Lil Jon - Crank it

The Synchronizers feat. The Evil Twin Of Paul Cless - Fuck That Shit

Apashe - Kannibalen

Dimitri Vegas & Like Mike - Tremor Ping Pong (DAWGS Edit) vs La La La vs I Like To Move It (DV&LM)