@^.*(youtu.be\/|v\/|u\/\w+\/|embed|e\/|watch\?v|\?v=|\&v=)([^#\&\?]{11,11}).*@igm

/*
Tested examples:
http://www.youtube.com/v/0zM3nApSvMg?fs=1&hl=en_US&rel=0
http://www.youtube.com/embed/0zM3nApSvMg?rel=0
http://www.youtube.com/watch?v=0zM3nApSvMg&feature=feedrec_grec_index
http://www.youtube.com/watch?v=0zM3nApSvMg
http://youtu.be/0zM3nApSvMg
http://www.youtube.com/watch?v=0zM3nApSvMg#t=0m10s
http://www.youtube.com/user/IngridMichaelsonVEVO#p/a/u/1/KdwsulMb8EQ
http://www.youtube.com/user/IngridMichaelsonVEVO#p/u/11/KdwsulMb8EQ
http://youtu.be/dQw4w9WgXcQ
http://www.youtube.com/embed/dQw4w9WgXcQ
http://www.youtube.com/v/dQw4w9WgXcQ
http://www.youtube.com/e/dQw4w9WgXcQ
http://www.youtube.com/watch?v=dQw4w9WgXcQ
http://www.youtube.com/?v=dQw4w9WgXcQ
http://www.youtube.com/watch?feature=player_embedded&v=dQw4w9WgXcQ
http://www.youtube.com/?feature=player_embedded&v=dQw4w9WgXcQ
http://www.youtube-nocookie.com/v/6L3ZvIMwZFM?version=3&hl=en_US&rel=0

See more: http://regex101.com/r/kW4bU8/1

*/