No spoken words said:
For me, The Wire is the best television show of all time. When season 4 ended a few months ago, I was literally saddened, just the best season of TV I've ever seen. If you've never seen it, do yourself a favor and rent or buy Season 1. You'll be hooked.
I keep hearing this from people, so I'll have to check it out one of these days.
I can't really say what I think the best show of all-time is, because I'm only 24 and have obviously missed out on a lot of great television that's simply older than I am. I do have to give The Honeymooners and I Love Lucy tons of credit for still being funny over 50 years after they ended.
But the best show I've ever seen has got to be Deadwood. Incredible writing, a perfect cast, and the sets and costuming were fantastic as well. And even though it's a drama, it can be funnier than any sitcom out there. Another great thing is that the episodes have a high re-watchability factor; because the dialogue is pretty dense, you always catch something new. I don't like westerns, but I loved this show.