LONDON -- 2016 has been a very bumpy, often fairly awful ride, but one thing that's remained a constant source of joy -- aside from J.K. Rowling's Twitter feed -- is Carpool Karaoke.

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Over the course of 14 episodes, a Christmas special and hundreds of millions of YouTube views, James Corden's viral series has brightened the internet on many, many occasions.

From rollercoasters to wrestling, here are some of the highlights...

1. Adele casually downing a mug of tea.

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With almost 140 million views at the time of writing, Adele's Carpool Karaoke is the most viewed episode of all time. And with good reason.

Not only was Adele's singing ridiculously good, but she was also just really, really funny the whole way through.

2. James Corden and Anthony Kiedis wrestling on somebody's lawn.

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There were many memorably moments in the Red Hot Chili Peppers' Carpool Karaoke -- the random spell of semi-nudity in the middle, for instance -- but James Corden and Anthony Kiedis' impromptu wresting match may well have been the highlight.

3. James Corden texting Leonardo DiCaprio from Jennifer Lopez' phone.

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It started with James Corden asking Jennifer Lopez about the most famous contact on her phone, then quickly escalated to him texting Leonardo DiCaprio for suggestions on how best to "cut loose".

The best bit? DiCaprio actually responded.

4. Selena Gomez taking James Corden on a rollercoaster.

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Normally Carpool Karaoke takes place solely behind the wheel, but every now and then there are detours.

A quick bit of rollercoaster-based singing during Selena Gomez' Carpool Karaoke was definitely one of the most dramatic ones.

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5. Bruno Mars and James Corden trying on hats together.

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The Bruno Mars episode of Carpool Karaoke was a lot of fun -- and that was largely down to how happy Bruno Mars was to be there (him and Corden genuinely got on like two old friends going for a drive).

The section where Corden attempted to prove Mars can get away with wearing any hat was especially enjoyable.

6. Elton John and James Corden singing "The Circle of Life".

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Elton John's Carpool Karaoke episode came complete with some glorious costume changes and plenty of powerful, belting harmonies -- but a dress-up version of "The Circle of Life" topped them all.

7. Madonna busting out dance moves in the passenger seat.

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From passenger-seat twerking to half hanging out of the window while Corden drove, Madonna really didn't hold back in her episode of Carpool Karaoke -- and the results were spectacular.

8. Lady Gaga taking the wheel.

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Picking a specific moment from Lady Gaga's Carpool Karaoke episode is tough; the whole thing is ridiculously good.

The moment when a mildly unnerved Corden lets Gaga take the wheel to test out her new driving skills (she'd only passed her test a couple of months before) is certainly up there, though.

9. Britney Spears and James Corden in matching schoolgirl outfits.

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James Corden wore a bunch of different outfits this year, but the schoolgirl uniform/pigtail combination he donned for Britney Spears' Carpool Karaoke episode was surely one of the most memorable.

10. The truly epic rendition of Les Misérables' "One Day More".

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The Broadway Carpool Karaoke episode -- which featured Lin-Manuel Miranda, Jane Krakowski, Audra McDonald and Jesse Tyler Ferguson -- was an absolute feast for the ears. Especially the sweet, sweet harmonies of "One Day More" that they belted out for the finale.

11. Michelle Obama and James Corden dancing to Beyoncé.

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You know your series is a success when the First Lady gets on board. From throwing shapes to Beyoncé's "Single Ladies" to a surprise guest appearance from Missy Elliott, James Corden and Michelle Obama's tour of the White House grounds is a thing of beauty.

12. Chris Martin spooning James Corden.

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In terms of being a pure, straight up joy to watch, Chris Martin's Carpool Karaoke was up there with Bruno Mars' and Adele's. Basically, the two of them just seemed to have a really lovely time together (it's not often a carpool session ends with some spooning and a tandem bike ride, after all).

13. Sia and James Corden rocking out with matching headgear.

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Sia's has got one hell of a powerful voice, but that didn't mean Corden couldn't keep up with her during her vocal chord-stretching Carpool Karaoke episode -- or match her impressive wig.

14. George Clooney and Julia Roberts crashing Gwen Stefani's Carpool Karaoke.

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Gwen Stefani's Carpool Karaoke episode was already off to a splendid start with the opening rendition of "Don't Speak", but when George Clooney and Julia Roberts joined the party for "Hollaback Girl" things went to the next level.

15. Finally, this glorious Christmas medley.

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What better way to round off the year than with a medley of "All I Want for Christmas" featuring Mariah Carey, Adele, Lady Gaga, and many of the other 2016 guests?

Here's to Carpool Karaoke 2017, and whatever new joys it may bring.

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