DVD buying - what's the point?

Thinking about movies a bit following the last post on The Prestige.
We just don't do movies much anymore. Obviously several things have caused this, but chiefly amongst them is having a child. Children and going out to grown up movies just don't mix.

But for a little while, the void in our movie going experience was filled with dvds. Very quickly the shelves started filling up with the things - and this was before you could pick them up as freebies with your newspaper or for the cost of a pint at HMV.

But after a few years of doing this, a few years of getting all those great movies of the past onto the shelves, we seem to have hit a full stop.

The main reason for it is our Amazon dvd rental package.
(And if you haven't got one of these, I can't recomend it highly enough - set one up now. Even better, use the amazon link on the Fictions page to do it.)
Every month we get a couple of dvds to watch and that does just fine. But it also makes me think about whether I really want to own something or whether just watching it once is all I really need. After all, most of the dvds left on the shelf are probably not going to be watched very often.
Same with books. I'm still on my book buying embargo. There are still at least 15 books on the shelf to be read. There's just no point buying any more until I've got some way through the unread ones.
And music is just the same. I'm finding I'm downloading more than I ever thought I would. But I really would like to find a decent, fairly cheap, legal download site. Any help?

Perhaps it's an important change in attitude. After all, I grew up in the time when you had to get something yourself if you wanted it. Things got deleted, music vanished, films weren't on constant rotation on numerous satellite channels. It was always the case that if you wanted to watch it/read it/listen to it you had to buy it.
But that just isn't the case anymore. I'm certainly not the only one who just doesn't buy stuff when it comes out anymore. I know it's still going to be available cheaper 12 months from now. Maybe then I'll get it. But more often than not, the desire to get it just isn't there after that time. I've managed without it and it's not that much of a hardship after all.