Among the many delights of "True Detective," which concludes its first season on Sunday night, has been the show's creepy, evocative opening credits sequence, which juxtaposes mundane imagery with the sort of dark symbols of sex and violence that Rust Cohle and Marty Hart deal with every day.

That title sequence continues a long tradition at HBO going all the way back to "Oz" (which had the show's creator Tom Fontana getting tattooed with the show's logo, interspersed with jarring prison imagery), "Sex and the City" (Carrie Bradshaw's fairy princess moment is ruined by a passing bus), "The Sopranos" (Tony takes the long, geographically illogical drive from Manhattan to his suburban Jersey home) and "Six Feet Under" (haunting images of our fragile mortality). Not every HBO show has been great, but you can usually count on them to have a notable opening; "How to Make It In America" was about as bland and forgettable as a cable comedy can be, yet the combination of Aloe Blacc's infectious song "(I Need A) Dollar" and images of scrappy, hustling New Yorkers was a sight to behold (and always suggested the promise of a much better show than what followed).

Title sequences are one of the many reasons I'm glad that HBO and other cable channels started making their own series, because "The Sopranos" et al began to rise just as the broadcast networks were starting to phase out long theme songs and credit montages. There had been an effort once before in the early '90s, after research suggested viewers changed the channel the second a theme song began; then came "Friends" and its catchy marriage of "I'll Be There For You" and images of Jennifer Aniston and Lisa Kudrow cavorting in a fountain, and title sequences got a reprieve. But as the hourly commercial load has risen, TV producers have had to choose between dumping long credits or dumping story time.

For understandable reasons, they've dumped the credits — or, in the case of a show like "New Girl," built a long-ish sequence that can be shrunk down to a few seconds as needed — which has left more time for plot and/or jokes, but in the process, they've lost one of the most powerful weapons for building a bond between show and viewer. When title sequences are done well, they vastly enhance the experience and serve as an effective lure to keep watching out of reflexive loyalty. The most dangerous time for me to channel surf is on the half-hour, because if I come across an opening credits sequence I like, it doesn't matter how terrible the attached show may be — say, "T.J. Hooker" — because I will be watching a large chunk of it, if not the whole thing.

While some credits sequences are simply a theme song slapped together with footage of the cast, there are three basic types of credits sequence: 

1. Opening Credits as Expository Device. These are your "Gilligan's Island" credits, your "Beverly Hillbillies" credits, even your "Streethawk" credits. Whether through song, narration, or a sequence of images, they make sure the audience understands the high-concept premise in a hurry so that nobody wonders what Mr. Drummond is talking about when he plays father to Arnold and Willis, or wonders which side of the Law/Order divide Lennie Briscoe and Claire Kincaid work on.

2. Opening Credits as Explicator of Theme. These often function as little short films that use images and music to tell you what the show is about. The credits on "Dexter," for instance, are a story of how everyday life is filled with unnoticed acts of violence. The "Star Trek" credits (which also have some exposition courtesy of Captain Kirk's "these are the voyages" monologue) sell you on a vision of wide-open space adventure. The "Cheers" credits suggest the long history and deep value of places where everybody knows your name.

3. Opening Credits As Setter of Mood. There's some overlap here with number 2, but these are more about trying to recreate the feeling the creators want you to have when watching a show than one that represents what the show is actually about. The Miller-Boyett T.G.I.F. shows like "Perfect Strangers" and "Full House," for instance, featured soaring ballads and celebratory images that didn't really capture the content of those shows, but gave you the warm fuzzies they expected you to feel for Cousin Larry or Uncle Jesse.

Across the history of television, there have been so many great title sequences — some attached to shows worthy of them, many not — that when Team HitFix got together to vote on our favorites, the recurring complaint was that no one could possibly vote for just 10, and even when we expanded the field to 25, it was damn hard. In the final results, embedded below, you'll note that there's no "Six Feet Under" (even though it's my favorite of all the HBO title sequences) and no "Dick Van Dyke Show" (whether the trip over the ottoman or the graceful side-step), but then when you look at what is there, well... there have been a lot of great opening credits sequences. Good luck clicking through without stopping to play many, many of the embedded YouTube videos. I'll just say that my week was much less productive as a result of this project — and also much happier.