TV on DVD - the opiate of the 21st century - has ruined movies for me. No matter what movie I watch, I can't help but be disappointed when the entertainment ends after just two hours. (And for this I spent $10?) The characters always feel underdeveloped, the plot too superficial. On the other hand, when I watch TV on DVD, when I curl up for several hours with the interns of Greys Anatomy, or the street dealers of The Wire, or the freaks and geeks of Freaks and Geeks, I end up forming serious emotional attachments. The characters develop depth and history; the plots are able to cultivate all sorts of intricate layers and connections.
I'm not saying that movies have gotten worse. Flags of our Fathers and The Queen were two excellent pieces of entertainment. But I couldn't help but be disappointed when they ended. They just felt so short and abrupt. I suddenly realized how difficult it is to squeeze so much story into 120 minutes. By the time the credits started rolling, I was just getting warmed up.
As Steven Johnson pointed out, TV on DVD is a new cultural phenomenon. Never before have we been able to sit back and watch a single narrative thread for most of a weekend. (Sure, there were TV miniseries, but the only miniseries I've actually enjoyed is I, Claudius.) It's as if our culture had been forced for most of the 20th century to just read short stories, to create dramas that can be compressed for a movie theater. Now, thanks to HBO, Netlfix, and DVD's, we can finally read some novels, and luxuriate in the sort of characters that just require lots of time.
I find TV on DVD to be fantastic, too - but for almost diametrically opposite reasons. For me, TV on DVD is great, because I can watch an episode and it will only take 22 minutes (or 45). Whereas I don't have the attention span for a whole movie, unless I'm at the cinema and there aren't blogs and music and reading and so forth to distract me.