Video download is the big problem because Internet Boss Google don't allow to monetize download site with Google Adsense. A download site receives more than million visitors per day and their server maintenance cost is so high. For this cause, they use few rate ad and for a better response, they use many hidden ads on their site and user feeling bored to download site. Sorry for some talking that you really not want.
I also used some site for download. But when I found Youtube Converter then to till today i use this site for download. I hope you also like and use think site for very fast downloads.
Go to http://youtube-converterx.com/
Copy a video link from Youtube
Paste this link to Youtube ConverterX
Click on Download Button
Youtube ConverterX shows you some format
Click a format that you want to download.