Watching a TV series is not a decision you can take lightly especially when it's ongoing. This kind of weekly or in-demand viewing requires a certain level of commitment.

You have to keep watching just to figure out what happens to the characters and the story. This gets pretty difficult when you have to sit through "challenging" episodes that make you want to throw your controller at the television.

We keep watching anyway, hoping that the story gets better and the cast finds their rhythm to make a spectacular show. An example of this in recent years is the high fantasy series, Game of Thrones.

Based on the books written by George R.R. Martin, the HBO series vowed to explore the world of Westeros. It had us by its dragon claws from the moment they showed what happened to those who desert the Night's Watch in the first episode.

It was incredibly exciting learning about all of the powerful players who wanted to rule the kingdom. We saw the rise and fall of several kings, queens, and storied houses (RIP, Lady Olena).

By the final season, expectations were pretty high. They set a high bar with their previous seasons and story arcs but they somehow tripped on the last one.

Once the finale finally aired, we were left with more questions and the unbelievable feeling of hollow disappointment. Despite its spectacularly bad ending, shows like Game Of Thrones have figured out how to keep an audience captive.

They kept us guessing who was eventually going to rule on the Iron Throne for over 7 seasons. Showrunners have another powerful weapon in their arsenal: cliffhangers and when to use them.

Here are some of the most remarkable cliffhangers on television to date:

These cliffhangers are so memorable, fans of the shows still remember them years later. Continue reading to find out some of TV's most talked-about nail-biters.

1. Grey's Anatomy: when they introduced McDreamy's wife

For MerDer fans out there, who can forget that scene in the first season when Dr. Montgomery introduced herself to Meredith by saying she must be the lady screwing her husband (Derek). Mer's face says it all.

2. The Walking Dead: when we had to guess who Negan and Lucille killed

I guess it's poetic that the 6th season of the show kept us waiting for 6 months before finding out who the evil duo killed. The scene was filmed from the perspective of the victim who could be any beloved character! (SPOILER: It was Glenn and Abraham)

3. Fringe: the freaking parallel dimension

Olivia gets transported to another dimension when she was about to meet Dr. Bell for the first time. We only learn she traveled to a parallel universe when the final shot pans out and shows they are standing inside the South Tower of the World Trade Center.

4. Breaking Bad: Hank finds out Walt is Heisenberg

In the mid-season finale, Hank was looking for a reading material to pass the time while he was using the toilet in Walt's house. He read the inscription on the book and finally connects the dots while fans had to wait for over a year for their inevitable confrontation.

5. ER: the doctors became the patients

John Carter was unfortunately stabbed by a mentally ill patient and he falls on the floor. We later find out that another character was stabbed; it was Lucy Knight and while Carter survives, she does not.

6. West Wing: who was shot?

The people in the White House were victims of a shooting. All we heard on the season finale were Secret Service agents asking who got shot and we had to wait for the next season to premiere before learning it was the President and josh who had been shot.

7. Buffy the Vampire Slayer: Buffy saves the world. Again.

Buffy sacrificed herself to save her sister, Dawn, and to seal a portal. While we've seen her die and get resurrected multiple times by that point, seeing her tombstone left a feeling of uncertainty about whether Buffy will come back again for almost 5 months until the new season.

8. Dallas: who shot J.R. Ewing?

The first show to execute a cliffhanger so flawlessly was Dallas. 83 million viewers tuned in to find out who shot Ewing.

9. The Office: will they or won't they?

We now know that Jim and Pam are end game. Those two agonizing seasons of them pining for each other were brutal and after Jim confessed his feeling and they finally kissed, we also wanted to know what the hell will they do next.

10. Sherlock: sorry, Dr. Watson.

Sherlock falls off a building during the second season finale. We all believe he died but apparently, he doesn't (wait for 2 years to find out how or did we really find out?)

11. Gilmore Girls: A Year in the Life: who got you pregnant Rory?

While Gilmore Girls is a lot more than just about the girls' love interest, their love lives are certainly a big part. We know Lorelai ended up with Luke but who's the father of Rory's baby? Will we ever find out?

12. Dexter: you're too late Dexter

Dexter thought he had saved his family from the Trinity Killer. When he goes home, he sees his wife dead in the bathtub while his baby cried, sitting in her pool of blood.

13. Game Of Thrones: Lord Commander Snow bleeds

The compassionate bastard of the north is betrayed by her own men when they take turns stabbing him. The season ends with Jon bleeding on a bed of snow as we wait for 10 months to find out if he is indeed dead.

14. Battlestar Galactica: they shot the commander!

Boomer is a Cyclon, Starbuck put two and two together but she didn't move quickly. The duplicate shot Commander Adama on the torso and we waited with bated breaths to see if he survived.

15. Alias: that's too much information!

Sydney finds out she wasn't Francie, she killed someone who looks like her best friend, and she wakes up in another country only to be told she's been missing for two years. WHAT!

16. Lost: the list won't be complete without this show

There's a reason why John was obsessively trying to pry the window on the hatch. It suddenly lights up and they finally realize there's more on the island left to be discovered.

17. The Sopranos: why was everything black?

The ending of The Sopranos leaves a lot to the imagination. Tony and his family were at a diner, innocently enjoying some onion rings while Meadow took some time parking then runs to the door, someone enters, the bell rings, Tony looks up, and it just cuts to black. Are they all dead?

18. Friends: Rachel

After a whirlwind romance, Ross and Emily tie the knot in London. Rachel decides last minute to attend her ex's wedding and Ross says her name instead of Emily's. It was months before it was revealed what happened after.

19. The Simpsons: who shot Mr. Burns?

The Simpsons took their shot at a Dallas-like episode of who shot Mr. Burns. Who in Springfield could do this? Turns out it was the baby.

20. Twin Peaks: there's a bigger mystery than who killed Laura Palmer

The amazing show endeavored to answer who killed Laura Palmer with the help of Agent Dale Cooper. In the 1st season finale, a new mystery has to be answered: who shot Agent Dale Cooper, and will he live or die?

Cliffhangers, when done right, make for great TV. Nail-biters just for shock factor rarely land and can even cost you some avid viewers.