I prefer this one, as well. It's more restrained, making the characters seem more real and, in turn, more affecting. I like the American version, too, but it tends to go over-the-top, which can be funny in its own way. I just prefer the subtler approach.
As for the DVD situation, I chalk it up to people being unfamiliar of the original show. BBCA isn't in everyone's cable package, and [adult swim], despite its relative popularity, still possesses a level of obscurity that keeps it out of the mainstream.