Big Bang Theory is perhaps the best sitcom I've ever seen. It features several nerds, including one of the most outstanding fictional characters - the nerd par excellence, the genius archetype, the rational scientist who deserves deep respect and admiration, despite his infantile features - Dr. Sheldon Cooper.
I've swallowed the entire series in about two weeks and I want more, and so do some of my friends (the fourth season is scheduled to start in September). The sitcom can be watched online (just google it). Some of the best parts are on YouTube - e.g. here and here.