As the final season of "The Sopranos" progressed and the bodies kept piling up, it became clearer than ever that Tony, the head of a New Jersey crime family played by James Gandolfini, wouldn't have a happy ending to his story in the 2007 finale, "Made in America."

Audiences didn't expect the show's final scene to be the Soprano family meeting at a diner while "Don't Stop Believin'" played on a jukebox. The camera showed the front door of the diner opening before cutting to black, ending the show.

People across the country thought HBO had crashed. But the show's creator, David Chase, made it clear that this was the end and that he had no intention of telling us whether the person who arrived at the diner was there to whack Tony.

By the time season five of "Game of Thrones" was airing in 2015, audiences knew not to get attached to anyone.

But if "Thrones" had a main character by season five, it was Jon, played by Kit Harington.

So when the season concluded with the episode "Mother's Mercy," in which his so-called brothers conspired to kill him via group stabbing, fans were shocked — well, the ones who hadn't read the books at least.

After the season ended, Harington swore he wasn't returning to the world of Westeros, which made viewers wonder: What would happen next? You'd have to tune in to season six to find out.

"The Walking Dead" waited until the finale of season six in 2016 to properly introduce viewers to Negan (played by Jeffrey Dean Morgan) after teasing him for the entire season.

And what an introduction it was. After terrorizing the main characters off-screen, Negan realized he couldn't decide who to kill and used a game to pick his victim in the episode "Last Day on Earth."

But we didn't get to see his selection — the camera switched to the point of view of the victim, who was then viciously bludgeoned by Negan's beloved baseball bat, Lucille.

Viewers didn't find out until season seven who was on the receiving end of Lucille's wrath.

"Star Trek" is a fairly episodic show by design. But when the season-three finale aired in June 1990, it became clear that even "Star Trek" knew the power of a good cliffhanger.

The third season ended with the episode "The Best of Both Worlds," in which Jean-Luc Picard (Patrick Stewart), the brave captain of the Enterprise, is taken captive by an evil alien species called the Borg, who have the power to eventually take over the galaxy.

Picard's friend and first officer, William Riker (Jonathan Frakes), is left with a choice: Does he mount a rescue mission or take the opportunity to wipe out the Borg, Picard included?

The episode concludes with Riker firing on the Borg's ship before hitting us with a "To be continued…" leaving Picard's fate up in the air until season four.

Throughout the first season of "Lost" in 2004 and 2005, fans kept getting hints that this wasn't your typical deserted island.

But in the episode "Exodus," when Jack (Matthew Fox) and Locke (Terry O'Quinn) blow the door off a mysterious hatch they found on the floor of the jungle and realize it goes deep underground, we get confirmation that something's wrong on this island.

Meanwhile, Walt (Malcolm David Kelley), a young boy on the plane, is snatched from a rescue raft by a mysterious group of people known only as the Others.

In retrospect, it's wild that we had to wait months to find out who took Walt and what was at the bottom of the hatch.

From the first episode of "Lost," it was clear each episode would split the action between present-day happenings on the island and flashbacks, usually focused on one survivor.

But the season-three finale, "Through the Looking Glass," which aired in 2007, seemed different. We watched as Jack became heavily depressed, even suicidal, and hooked on painkillers, a previously unknown part of Jack's history.

But the last scene of the finale showed us that this wasn't a flashback but a flash-forward, letting us know that at least Jack and Kate (Evangeline Lilly) would be rescued from the island at some point and that Jack would tearfully tell Kate they had to go back to the island, changing the course of "Lost" forever.

By the time "Dallas" entered its third season, audiences were captivated by the wheeling and dealing of the Ewing oil/cattle dynasty.

And no character was more admired (or reviled) than J.R. Ewing (Larry Hagman), a scheming oil tycoon who stopped at nothing to get what he wanted.

When the season-three finale, "A House Divided," concluded with his shooting by a mysterious gunman, TV audiences became consumed by the question "Who shot J.R.?"

It could've been anyone, as everyone on the show had a reason to kill J.R. In fact, everyone on the show was filmed shooting J.R. to keep it a secret from audiences and the crew alike.

It took four episodes of season four before the shooter's identity was revealed.

Fifteen years after the "Dallas" episode, "The Simpsons" concluded its sixth season by showing Mr. Burns (Harry Shearer), the greedy owner of the Springfield Nuclear Power Plant, getting shot.

The first part of the episode contains many clues (and some red herrings) about who shot Burns — but as with Ewing before him, everyone had a reason to want him dead.

We won't spoil it here, but the season-seven premiere clarifies who shot Burns, and the reveal's certainly worth the wait.

"The West Wing" became a phenomenon throughout its first season in 1999 and 2000, but it took the cliffhanger in the season-one finale ("What Kind of Day Has It Been") to put it on the map.

The senior staff of President Jed Bartlet (Martin Sheen) is at an event where the president's speaking when a gunman opens fire.

In the chaos, we see each member hit the ground. But before we can assess who's safe, the camera pans out, and we hear a frantic Secret Service agent over the radio asking who's been hit.

We didn't find out the answer until the season-two premiere months later.

This wasn't a season finale, but it was still very nerve-racking to wait a week to see if President Fitzgerald Grant III, played by Tony Goldwyn, had survived getting shot while entering his birthday party.

The season two episode, "Defiance," was wild enough without the attempt; it was mainly about James, a reporter, investigating the claim that the voting machines had been rigged in the election that resulted in Fitz's win.

But then, in the last two minutes — bang. Fitz was shot by an unseen assailant, thrown back into his limo, and rushed to the hospital, his fate unknown.

The next episode, "Happy Birthday, Mr. President," revealed that Fitz was alive, but he wouldn't wake up for a few more episodes. Classic "Scandal" drama.

It's impossible to predict what will happen on "Twin Peaks," which began as a murder-mystery show and ended as something quite different.

In the first season, the show's creator David Lynch mainly adhered to the mystery aspect of the show, down to the last moments of the finale, when FBI agent Dale Cooper (Kyle MacLachlan), the main character, is shot on his doorstep by an unknown gunman.

There are theories to this day about the identity of Cooper's would-be killer, making it an all-time cliffhanger.

Season one of "Grey's Anatomy," which aired in 2005, had a lot of characters to juggle, but perhaps the most compelling plot line at the time was watching Meredith Grey (Ellen Pompeo), a surgical intern, fall in love with her boss, the neurosurgeon Derek Shepherd (Patrick Dempsey).

It seemed they'd finally figured out their issues in the finale of season one, "Who's Zoomin' Who?" — only for a statuesque redhead (Kate Walsh) to greet Derek and say to Meredith, "You must be the woman who's been screwing my husband."

Around the country, jaws dropped. Answers would come months later, in season two.

Ross (David Schwimmer) and Rachel (Jennifer Aniston) were one of the greatest will-they-won't-they couples of our time.

It was a huge surprise when Ross decided to marry Emily (Helen Baxendale), his British girlfriend of only a few months, in the 1998 finale of season four, "The One With Ross's Wedding."

But the pull of Ross and Rachel's unfinished business was too strong for Ross, and viewers (and Rachel) gasped as Ross said, "I, Ross, take thee, Rachel" at the altar.

The officiant asks Emily if he should continue. Before we find out her answer, the episode ends, leaving Ross' marital status up in the air until the season-five premiere, aptly titled "The One After Ross Says Rachel."

"Alias" starred Jennifer Garner as the superspy Sydney Bristow and Michael Vartan as Vaughn, her handler.

Their explosive chemistry was a huge part of the show's success, but it became increasingly ridiculous that these people wouldn't fall in love by season two.

And so they did — until the season-two finale, "The Telling," in 2003. After surviving a particularly nasty fight, Sydney wakes up in Hong Kong, asking for Vaughn.

He arrives, only to tell Sydney that she's been missing for two years and that in that time he's married someone else. A true gut punch, even 21 years later.

Throughout the first five seasons of "Buffy," the titular vampire slayer (Sarah Michelle Gellar) gave more of herself than any teenager should be expected to give.

But in the season-five finale in 2001, titled "The Gift," she sacrificed herself to save her sister, Dawn (Michelle Trachtenberg); her friends; and the town of Sunnydale.

The episode's final shot is a close-up of Buffy's gravestone, which declares: "She saved the world. A lot."

How could there be a season six of "Buffy" without Buffy? Fans were asking this question until the show came back and it became clear that Buffy's death would have long-term consequences for the show.

Throughout the first episode ("Be Still My Heart"), Lucy Knight (Kellie Martin) is trying to tell her boss, Dr. John Carter (Noah Wyle), that she's concerned about her patient's mental state.

Busy with other things, John ignores her, with disastrous consequences. The patient stabs them both, and the episode ends with a haunting image of John and Lucy staring at each other on the floor next to a hospital bed.

That's nothing compared with what happened the following week when their colleagues found them in this state, in the episode "All in the Family."

"How I Met Your Mother" frequently employed cliffhangers — in fact, the whole show could be considered a cliffhanger, as Ted didn't meet the titular mother until the series finale.

But one of the longest-running cliffhangers was first hinted at in the premiere of season six, when the gang was seen in the near future attending a wedding where Ted was the best man — but fans didn't get a glimpse at the bride or the groom.

That is, until the season finale when it was finally revealed that the groom was notorious womanizer and commitment phobe Barney Stinson (Neil Patrick Harris).

But who was the bride?

We had to wait an entire season until the finale of season seven, when it was finally revealed that Barney would eventually marry Robin.

And then they lived happily ever after, as long as you ignore the events of the controversial series finale.