Most Exhaustive Free Videos for Commercial Use on Internet

In 2002, for the first time cell phones with built-in cameras appeared in the market. Over years the price to acquire a good quality camera has decreased. More and more people use the mobile cameras as their primary camera. And... the high speed internet is getting cheaper every day. Well... where is all this leading to? For one thing, people are contributing to the b-rolls in high numbers. What costed hundreds of dollars just a decade ago is today free for all to use. Here I have listed a few websites that offer very good quality videos for free.

Among this list CC0 is the best license type where you would not have any restriction whatsoever.
CC-BY means that you are expected to mention the source of video and give due credit to the author or the website. Other have a sweet mix of different licenses for different videos.