converting youtube videos

Upfront disclaimer: I have no life.

Now....when downloading a youtube video with download helper, I notice there are usually 4 or 5 choices fl, hd, mp4, whatever. There is also a menu choice to convert the file.
Is there a simple rule of thumb to get a decent quality video with decent sound quality, which choice is the best? Or should I choose the convert option, and if so convert it to what?
Ultimately I just like to view the videos on my pc....don't plan to burn it onto a dvd or do anything else with it.
Thanks.

 

You can use DVDVIDEOSOFT.
They have many great programs - converting AVI;Youtube downloader, etc.
The program will convert it so you can watch it on PC or burn to DVD.
The programs are free and there is no trial period or watermarks.

 

I use download helper too, I just leave it as .flv.