I just started binging The Leftovers, and the opening credits change utterly from season 1 to season 2. I haven’t watched season 3 yet, but apparently it uses the same graphics as season 2 but goes up to 11 with its weird fixation on Perfect Strangers.
So any other openings come to mind that are hugely different? (Monk also comes to mind.)
Queer as Folk changed their opening credits around season 3 or 4. They changed their opening theme song from an upbeat song to a creepy slow song.
Doctor Who (understandably) has overhauled its title sequence numerous times over 50-ish years.
Mrs. Nonsuch and I have been catching Alice reruns on Antenna TV, and the opening for the first two seasons basically depict the start of the show: Alice’s car breaks down, she gets an apartment, she gets a job at Mel’s, etc. Once the third season came along, the titles changed to reflect that Alice is no longer quite the “new girl in town.”
Lost in Space changed its opening, dispensing with the animation, and substituting a jazzier theme, after the first couple of seasons.
*Treme *kept the theme music, but changed the visuals each season: Treme (TV series) - Wikipedia
(On David Simon’s previous show, The Wire, the graphics did change a bit from season to season, but the theme song was reinterpreted by a different artist/group.)
*True Detective *changed its credits from the first to second season, though that was pretty much a given since there was no continuity of characters or setting between them: True Detective - Wikipedia
(Season Two of TD also ran different verses of Leonard Cohen’s song “Nevermind” over the credits of each episode.)
The first season opening of The Dick Van Dyke Show used a bunch ofstill shots and photos and a different version of the theme song.
The Twilight Zone had several different openings in its early years. Not to mention an entirely different one for the pilot that didn’t feature Rod Serling.
*The Cosby Show *had different credit sequences and theme songs every season.
*Happy Days *also changed their theme song twice.
The Aquanauts/Malibu Run changed their lead actor, title, and concept midseason. I would assume they changed the credits, too.
The great thing watching Dick Van Dyke as a kid was waiting to see if he did a pratfall over the ottoman. They’d intersperse a version where he did a jazzy little sidestep and stayed vertical.
Red Dwarf season 3 onwards. (different clips every season)
Frasier always had cute little changes to the cityscape on his opening title. And the pix of famous friends at the end. And his song sometimes changed.
Star Trek: Deep Space 9 added more CGI to their opening to depict more going on (ships coming to and fro, people working on the station, etc.)
Japanese anime series completely change their opening credits every 12-13 episodes. I do mean completely: they’ll use a new song and a new animation sequence. Occasionally they’ll even change them more often. For example, the second season of Yuki Yuna is a Hero consisted of two completely different stories spanning 6 episodes each, and they had two completely different opening credits. They went even farther with the closing credits: as I recall, each of the first 6 episodes had their own credits sequence, and they used 3 or 4 different songs (although they didn’t animate these, instead using still frames). The final 6 episodes shared the same closing credits.
Another notable example is School-Live!. The opening credits feature a saccharine sweet song with images of the main cast having fun in their school club. The first episode eventually reveals that all this is a delusion in the head of the main character: in reality, the cast are the only survivors of a zombie apocalypse, barricaded in what remains of their high school. Over the course of the series the opening credits slowly change to actually reflect reality: the school becomes grungier and unmaintained, zombies start to accumulate outside of the school, and shots of characters who are only alive in the main character’s delusions gets replaced by zombies or a picture of their grave. This all reflects the main character’s gradual acceptance of reality over the course of the series, which I think is a pretty neat thing to sneak into the credits.
Mission: Impossible has different opening credits for every episode. Same basic format, but incorporating clips from the episode you’re about to see.
When Call the Midwife moved from the '50s into the ‘60s, the still photos of London’s Poplar District got colorized. The better to match Brits’ snapshot memories of the era, I guess.
Sitcoms like Friends and Big Bang Theory get recut intros with new scenes and more recent pictures of the cast. Sometimes the original intro was put together from only a few scenes taken from the first 3 or 4 episodes.
And shows about maturing families, such as Modern Family or the original Roseanne, get updated intros for obvious reasons.
Babylon 5 changed their opening credits each season, there was basically a recap of the story so far that updated as the show progressed.
Crazy Ex-Girlfriend has had three awesome theme songs and credit sequences, that are then referred back to within the context of the show, like Trent’s reprise of the season 2 opening number.
Big Love had a few different iterations, which I thought suited the stories being told.
The Drew Carey Show started out with these simple cartoony credits, to the song of Moon Over Parma.
Then, after doing some special funny credits as a one-off using the song Five O’Clock World, they then turned an edited version into the official credits.
Then later still they changed again to a song called Cleveland Rocks. I think these stayed to the end.
Aqua Teen Hunger Force changed their credits and theme song annually in seasons 8, 9, 10 and 11.
South Park and I guess you can count the Simpsons, as well.