First off, if you already haven't seen the show firefly, you should. (its off-air, but you can still find it in stores)
Having said that, in the show the characters have such great lines, and their speech is so beautifully crafted. I'm sure there are other shows out there that also have amazing lines, and I was wondering why you only hear great lines in shows and movies? Clearly the writers who came up with them were real people, yet you don't hear great lines that frequently.
If you ask me: Today's folk have: talk first, think later syndrome? Basically, we go about our days in such hurries, we communicate what we need, and then move on. As to the writers in the shows, they've thought about the words a lot (after all they are paid to do so) and therefore, create such articulate conversations, and great dialog.
So whats stopping us from thinking a little more in our days? If there is anything we've learned from the play "Our Town" it would be to take life a little slower. The slower we go, the more time we have to think.. Maybe then we could be more frequently amused by great lines.
(Not to say that its not OK to have humdrum speech, rather I would be thoroughly amused with regular quips.)
More to come, if more comes a'knocking.