I'm going to avoid the obvious ones that I love (The Simpsons, South Park, Family Guy etc) and say The X-Files and Twin Peaks. Two of the most intelligent and knowing TV shows, I'm proud to say I've seen every episode of each at least five times (and am currently going through seasons one and two of the former again). The X-Files can make me laugh, cry and is much more intelligent than it's given credit for, while Twin Peaks is one of the most visually arresting TV shows ever. That's not to mention the endlessly exciting cliffhangers and amazingly complex surrealist thread running through it. I recently watched the first season again and was reminded how good TV can be. Sadly, nothing like Twin Peaks would get made nowadays. It's just far too intelligent and original. And, no, Lost isn't even in the same league as Twin Peaks because it is, at heart, a cynical attempt at being as odd and "quirky" as Twin Peaks.