The best and easiest way is YOuTubeDownload Helper, there is no better.
It is integrated in the browser itself as an addon, there is no need for
conversion or wait time, you open the video and there is a download
button right there and even in different formats suck as .flv, .mpg and mp3.
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Cubase 8.5 Pro. Windows 7 X64. ASUS SaberTooth X99. Intel I7 5820K. ASUS GTX 960 Strix OC 2GB. 4x8 GB G.SKILL.
2 850 PRO 256GB SSDs. 1 850 EVO 1TB SSD. Acustica: Nebula Server 3 Ultimate, Murano, Magenta 3, Navy, Titanium.