I found this video whilst browsing YouTube. In it, Charlie Brooker, lead television critic for the UK's Guardian newspaper, does a pithily excellent job in explaining just why The Wire really is the best show on television. What's even more telling is the fact that he made this video without having yet seen the fourth season, which is regarded by most as the best season of the show.
Anyway, here's the video. It's well worth watching if you want to learn a bit more about The Wire and it's only four minutes long.