What's your preferred method of buying and owning digital movies...if you do so?

I know one can get movies digitally via their cable provider, and through their PS3 or XBox 360, but I understand these're often just temporary rentals.

How can I keep and file away a movie digitally, besides the traditional illegal downloads, which may or may not be plagued with malicious viruses and spyware?

Buy a physical copy and rip it yourself?

They're copy-protected. At least, most of them have been up until now...besides, the whole point is to avoid having to go to the trouble of going to the store to pay $10 ~ 30 for something that's going to become worthless (money value wise) the second you take the plastic wrapping off of it.

More and more movies these days that you buy in store come with an extra disc that is a digital copy you can transfer to your computer...  I suppose this is one legit way of having that.  But it means you have to still buy the physical copy.