D and I have recently become addicted to House, the Fox show about the grumpy gimpy doc who solves medical mysteries. I was first intrigued by the frequent references to it on TV writer Jane Espenson's blog, and when she kept pointing out the title character's similarities to Sherlock Holmes-- well, that was an easy sell.
Structurally, the show is very similar to Law & Order Classic: a cold open featuring the victim succumbing to his or her ailment, followed by four acts of misdiagnoses and treatments-- which slowly reveal more about the nature of the illness-- and often a B-plot featuring supporting characters, before the resolution in the fifth act.
Formulaic, yes, but that's part of what makes it so satisfying. I love watching intelligent, competent people solve difficult problems. And unlike L&O, the personalities and personal histories of the individual characters actually figure into the stories. You might think this means I also like the L&O spinoffs, especially Criminal Intent, but you'd be wrong. TV shows must strike a delicate balance between plot, character, and tone, and many contemporary cop dramas just don't do it for me. (BBC's Life on Mars is a different story. Literally.)
House is on a brief hiatus right now, but we're burning our way through the first season on DVD. Love that Netflix!