Grey's Anatomy (ABC)

GREY'S ANATOMY is a hospital-set dramedy that follows the lives of five interns (who, over the course of the series, become full-fledged doctors) as they adjust to their new surroundings at Seattle Grace Hospital. The series' opening scene takes place during the awkward morning after a one-night stand between the show's namesake, Meredith Grey (Ellen Pompeo), and neurosurgeon Dr. Derek "McDreamy" Shepherd (Patrick Dempsey) -- who, as it turns out, also works at the hospital. From there, the story evolves to include other interns, tenured doctors and the various patients they treat.

The Grey's Anatomy writers have proven that they're not above ridiculous plotlines involving ghost sex, a patient who wants butt implants, or a crazy man walking around with a bomb inside his body. But aside from the soapy, sexual overtones, what has so many people hooked on Grey's is the complexity of its characters. So while Meredith is beautiful and smart, she's also remarkably flawed -- and as the series goes on, her story only deepens.

The same can be said for other ensemble members: For example, while Cristina (Sandra Oh) provides most of the comic relief through cunning wit and side-splitting dialogue, she, too, goes through life-altering moments. Over time, these are characters you become attached to -- and grow to love.