First, Check out the Basshunter Dota Video:

How to Download and View
1- You can direct download basshunter dota video by clicking HERE
(Dont forget to rename it to .FLV)

2- Read THIS and you will actually be able to download more stuff from youtube very easily in the future.

3- Another good option is by checking out KeepVid. You can enter the URL of your favorite video (Basshunter Dota in this case) and click download, it will show a direct download link instantly.

How to View:

After downloading, you can either view it in VLC or Media player classic or convert it to AVI. Check out this software where you can convert your youtube videos to AVI.

I hope this helps.