# To download a video in 720p MP4:
youtube-dl -f 22 example.com/watch?v=id

# To download a video in 720p MP4 or WebM or FLV:
youtube-dl -f 22/45/120

# To list all available formats of a video:
youtube-dl -F example.com/watch?v=id

# To download a video to /$uploader/$date/$title.$ext:
youtube-dl -o '%(uploader)s/%(date)s/%(title)s.%(ext)s' example.com/watch?v=id

# To download a video playlist starting from a certain video:
youtube-dl --playlist-start 5 example.com/watch?v=id&list=listid

# To simulate a download with youtube-dl:
youtube-dl -s example.com/watch?v=id

# To download audio in mp3 format with best quality available
youtube-dl --extract-audio --audio-format mp3 --audio-quality 0 example.com/watch?v=id

# For all video formats see
# http://en.wikipedia.org/wiki/YouTube#Quality_and_codecs