Well, to me I consider the minimum possible quality for a video, below that I don't bother downloading it. But of course, I'm always looking for the highest quality, there is nothing better than watching bears in HD.
But you have to consider here that you have to keep your upload amount not too far from your download amount. So sometimes it's hard to download a 20 minutes video with more than 1gb. You have to consider if it is really woth it, hehe.
