'How I Met Your Mother': 9 Must-Watch (or Rewatch) Episodes

"How I Met Your Mother," which wraps Monday, has long been a romantic epic with a laugh track — with the emphasis on the "long" part. The series has logged nine seasons, zigzagged back and forth in time more than "Lost" (which only ran six seasons), and journeyed through dozens of fraught relationships and dead-end hookups as Ted Mosby (Josh Radnor) searched for the mother of his children-to-be.

If you're not prepared for a 75-hour, binge-watching marathon (with 75 hours being approximately how long it would take you to watch, or rewatch, the 206 half-hours leading up to the two-part finale), then here's a manageable list of some of the essential "How I Met Your Mother" episodes that — either for their key plot revelations or their glorious "Mother"-ness — you should be sure to bank by the time Ted finally meets you-know-who (played by Cristin Milioti).

1. "Pilot" (Season 1, Episode 1)

First outings for episodic series are often not much more than curiosity pieces: Oh, remember when so-and-so's hair looked like that? Or, that guy really put on the pounds over the years, huh? But this is not the case with "How I Met Your Mother." "It's stunning how important the pilot of this sitcom is," Donna Bowman, who covers the series for the A.V. Club, said in an email. For starters, it puts Ted's children of 2030 on the couch (where they'll stay in banked footage for the remainder of the series) and lets Dad start spewing every detail of his romantic life (because he's such a romantic).

"In many ways the show keeps going back to [the pilot], over and over again," Bowman said, "and you can't understand the show without it, not just the premise but the themes and characters."

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2. "Arrivederci, Fiero" (Season 2, Episode 17)

This is a pick by Radnor. "I love the episodes that fill in a lot of the lore and backstory," the star told Thought Catalog. And this episode, about the twilight of the car that made friends of Ted and Marshall (Jason Segel), and Robin (Cobie Smulders) and Lily (Alyson Hannigan), does just that.

3. "How I Met Everyone Else" (Season 3, Episode 5)

This is another of Radnor's favorites — and another of Bowman's must-see picks. "A masterful example of the nesting timelines the show uses to deepen the simple flashback structure," Bowman said of the episode about the girlfriend (Abigail Spencer) who is more threatened than entertained by how intertwined Ted's gang is. As an added bonus, there's a flash-forward to a college reunion that Ted, Marshall, and Lily attend (they all met in college, you see) at which the Ted of 2020 references his wife (but, oddly enough, doesn't yet have the Bob Saget voice he'll affect in 10 years).

[Related: 'How I Met Your Mother' Racism: Creators Apologize for Kung-Fu Slapsgiving Episode]

4. "Three Days of Snow" (Season 4, Episode 13)

Buddy TV's John Kubicek told us, via Twitter, that this episode, which is mostly about an airport ritual of Marshall and Lily's, "exemplifies the show's misdirection, complex narrative structure, comedy and heart for me."

5. "Girls Versus Suits" (Season 5, Episode 12)

The series' 100th episode, further distinguished by a full-scale, musical number starring Barney (Neil Patrick Harris), is a true Mother lode that puts Ted in the same apartment of his future wife. If you've previously watched "No Tomorrow" (Season 3, Episode 12), you'll recall the Mother's yellow umbrella (that Ted found at a bar), and you'll know Mother by the sight of it in "Something New" (Season 8, Episode 24).

[Related: A Closer Look at the Farhampton Inn Set of 'How I Met Your Mother']

6. "Challenge Accepted" (Season 6, Episode 24)

This episode is its season's finale, and, in general, the finales are the best (and/or fastest) way to catch up with plot twists both major (Lily's pregnancy) and even more major (Barney's surprise farewell to bachelorhood).

7. "Ducky Tie" (Season 7, Episode 3)

Sometimes, even in a intricately plotted comedy series, it's the comedy that shines through. "One of the flat-out funniest episodes the show has produced," Bowman said of the half-hour about Marshall's, yes, ducky tie.

8. "The Time Travelers" (Season 8, Episode 20)

Future Ted (and in the context of the episode, if not the entire series, the concept of Future Ted is one that makes perfect "HIMYM" sense) visits his future but still-unseen wife and tells her that they'll meet in 45 days. It's romantic and lovely — and it spurred E! Online's Jenna Mullins to theorize that the series is trying to tell us that the Ted of 2030 is a widower.

[Related: Is the Mother Dead? 4 Clues From 'How I Met Your Mother']

9. "The End of the Aisle" (Season 9, Episode 22)

It's time to get caught up, already. This is the penultimate episode that aired last week. Robin and Barney's seasonlong wedding day finally gets them to the altar, and the Mother, of all people, helps get them there when she meets Robin, and, in the process, bookends Ted's love journey.

The "How I Met Your Mother" series finale airs Monday, March 31 at 8 p.m. on CBS.