Last week I watched two very interesting movies (documentaries actually) - The Lost Mustangs (National Geographic) and America's Heart and Soul. What's significant about that is that both of them were titles that I would have normally had to rent on DVD. Instead I "rented" them from Movielink.com, downloaded them to my Media Center PC, and watched them from there.
I have a cable broadband connection with 6 megs of bandwidth so the movies only took about 10 minutes to download each time. When I started watching them I was immediately impressed by the video and sound quailty. It was at least as good as DVD and maybe even a little better (on my 32 inch HDTV screen).
I don't know that I would use this service to rent regular movies (I still like DVDs because of the special features), but it was very nice to be able to rent titles that I can't normally get at my local video store. Movielink also offers some HD titles to download and I may give a few of those a try.