I don't have cable, and I never really watched broadcast TV. Which means I only started to become familiar with "The Big Bang Theory" through YouTube in the last couple years. YouTube proved that the series has a number of brilliant comedic moments (the Leonard Nimoy napkin is at the top of the list), and I finally decided to acquire the first season ... a used DVD set of the first season cost $5 at BMV. At which point I found out that almost the entire season is on YouTube as "highlights," because I'd seen nearly all of it. Still, it was fun to watch the series through.
Howard Wolowitz (Simon Helberg), Raj Koothrappali (Kunal Nayyar), and Sheldon Cooper (Jim Parsons) are all varying degrees of horrible - not evil, but simultaneously super-intelligent and blind to their own flaws. Leonard Hofstadter (Johnny Galecki), who is Sheldon's roommate, acts as an apologist for all of them - but particularly Sheldon - and the voice of sanity, with the lovely Penny (Kaley Cuoco) as the only normal human in the mix. All of which is kind of meaningless to explain as almost everyone already knows the story.
And ... they hired a Ph.D. in Physics as a consultant so every technical reference on the show is accurate. This seems obvious, but most movies these days casually ignore the reality of physics. It's a pleasure to watch a show about science that's not full of technical gaffes.