The 10 Best Arrowverse Episodes of 2017

"Raiders of the Lost Art"

Admittedly, there are a lot of Legends of Tomorrow episodes that deserve a spot on the list. (Hello, "Helen Hunt".) But when it comes to Legends' history-hopping adventures in 2017, "Raiders of the Lost Art" is definitely something else.

The episode saw the Legends and the Legion of Doom traveling to 1970s Los Angeles, where Rip had been time-displaced as a Hollywood director. As they soon discovered, Rip was working alongside a familiar face: a young George Lucas (Matt Angel). If George ended up being kidnapped by the Legion of Doom, he would end up giving up filmmaking altogether, and Star Wars' effect on the world would completely disappear.

What unfolded was a sort of unabashed love letter to the Star Wars franchise, complete with laser guns, a trash compactor escape, and way too many Easter eggs to mention here. It also proved just how great Legends can be when it relies on the sort of delightfully-campy premises that have to be seen to be believed. And along the way, it showed audiences just how much of an impact Star Wars has had on our culture, and how many people it has inspired along the way.

"Duet"

Sure, "Duet" might not have resonated with every Arrowverse viewer, especially those who weren't expecting their favorite superheroes to spontaneously break into song. But the Supergirl and The Flash musical crossover definitely found its audience - from former Glee fans, to musical theater junkies, to just people enjoying whatever ride the Arrowverse decides to take them on.

The episode saw Kara and Barry stuck in a Old Hollywood-set musical dream world, which they were thrown into by Music Meister (Darren Criss). The mysterious and charming villain left the pair with one task: go along with his musical, or die.

Whether or not you liked "Duet", it's hard to argue just how ambitious the mini-crossover proved to be. From the production value and surprise appearances, to its songs written by award-winning composers, "Duet" showed what kind of unique television experiences the Arrowverse is capable of. Plus, come on, you'd be lying if you said you didn't get emotional during Barry's rendition of "Running Home to You."

"City of Lost Children"

The second half of Supergirl's second season introduced viewers to so many different corners and elements of the DC Comics cosmos. While that played a role in "City of Lost Children", it was the episode's human elements that helped it rise above the pack.

The episode saw James Olsen coming to terms with his role as Guardian, and how exactly that translated to National City's public. He got his answer by helping Marcus (Lonnie Chavis), a Phorian boy whose mother had been responsible for an attack in the city.

By giving fans a Jimmy Olsen story that would have probably seemed unthinkable pre-Supergirl, "City of Lost Children" proved to be one of the most unique installments of Supergirl yet. The episode tackled what it means to be a superhero that isn't the show's titular hero (something the Arrowverse is no stranger to doing), but crafted its own heartfelt story in the process.

"Infantino Street"

Admittedly, some viewers weren't the biggest fans of The Flash's main plot for the first half of 2017, as Team Flash scrambled to stop Iris' impending murder. But regardless of how you felt about the storyline, "Infantino Street" was a pretty impactful climax.

With the clock quickly running out until Iris' death, Barry decided to resort to desperate measures -- mainly, teaming up with Leonard Snart to steal a piece of ARGUS alien technology. They try to pull of the heist, crossing paths with King Shark in the process, but are ultimately caught. The team then braces for the altercation between Iris and Savitar, which seemed destined to meet its heartbreaking end.

While The Flash often focuses on the lengths that Barry would go to to save somebody that he loves, "Infantino Street" took things to a whole other level, something that would carry right over to the season finale. In the process, fans got a Barry/Snart team-up they'd been anticipating for quite a while, especially as Wentworth Miller seemed on his way out of the Arrowverse.

Plus, that video message scene - you know the one - was possibly one of Candice Patton's best moments on The Flash.

"Lian Yu"

While all of the Arrowverse season finales offered some sort of shocking conclusion, Arrow completely blew things out of the water (pun intended).

After tormenting Oliver for the entire season, Adrian Chase/Prometheus (Josh Segurra) unveiled his grand finale. Chase led Oliver to Lian Yu, each of them with a ragtag team of heroes and villains in tow. Chase promised that the altercation would be deadly, and as the closing minutes proved, he meant it.

"Lian Yu" completely changed the trajectory of Arrow, causing fans to speculate for months about the safety of their favorite characters. In the process, it provided a worthy bookend to Oliver's five years of flashback hell, truly signifying the start of a new era. And if that wasn't enough, the stellar action sequences and Stephen Amell's heartbreaking performance were icing on the cake.

"Mixed Signals"

Leading up to Season Four, The Flash promised to bring back the sort of upbeat sensibility that fans fell in love with. And it's safe to say that they did so with "Mixed Signals".

After Barry made his epic -- and confusing -- return from the Speed Force, he was ready to adjust back to normal life as the Scarlet Speedster. But between an overly accessorized suit, awkward bouts of couples therapy with Iris, and a new, technology-based villain, that definitely didn't go as planned.

The episode gave fans plenty of delightful moments to chew on, from Barry's Risky Business homage to the various mishaps with his new suit. It also gave fans the first hint at the direction for this season's villains, something that certainly taken the spotlight in the weeks since.

"Deathstroke Returns"

As we previously mentioned, Arrow's sixth season helped take things into a new direction. But it perhaps was at its strongest when revisiting the past - particularly with Slade Wilson/Deathstroke (Manu Bennett).

The fan-favorite made his surprising return in the back half of Arrow's fifth season, and it was clear that Oliver still owed him a favor. As the name would suggest, "Deathstroke Returns" saw Oliver and Slade reuniting to locate Slade's son, Joe Wilson (Liam Hall). In the meantime, Team Arrow finally uncovered the mystery of Vigilante's identity, putting the villain's entire arc in a new light.

What transpired was equal parts action and emotion, and definitely a standout of Arrow's sixth season thus far. And that climactic Deathstroke fight scene in the episode's end certainly made the years of Bennett's absence from the show worthwhile.

"Midvale"

Some would argue that flashback episodes -- especially those that barely feature a show's stars -- are a pretty big risk. But in Supergirl's case, "Midvale" ended up being exactly what the show (and possibly the fandom) needed.

"Midvale" followed Kara and Alex traveling back to their hometown, hoping for a little rest and relaxation to get over their respective breakups. From there, the episode transitioned into a lengthy flashback, which followed teenage Kara and Alex through a pretty unique situation. After a mutual friend was murdered, the sisters decided to get over their differences and uncover the truth.

The end result was heartwarming, unpredictable, and contained more Super-family Easter eggs than fans had ever expected. Along the way, it brought Supergirl back to the sisterly dynamic that has always been at the show's core.

"Beebo the God of War"

Arguably, each Arrowverse show went on a sort of epic high note to close out 2017. But none were as enjoyable or almost unexplainable as Legends of Tomorrow's midseason finale.

"Beebo the God of War" saw the Legends in a rather odd predicament, as they uncovered an anachronism in Viking-era Norway. The anachronism was none other than young Martin Stein (Graeme McComb), who had been transported back to the time alongside his Christmas present for his daughter. The stuffed toy - known as Beebo - quickly became embraced by the Vikings, who accepted it as their new god.

On paper, that concept sounds pretty ridiculous. And within the episode, it's admittedly pretty ridiculous. But it was an absolutely delightful thrill ride that led to plenty of laughs, memes, and even a new holiday from the show's fans. And in the process, the episode proved to be pretty heartfelt, providing fans with a sort of time to grieve the loss of one Legend and the departure of another.

"Crisis on Earth-X"

And finally, the Arrowverse exceeded all expectations with "Crisis on Earth-X", this year's four-show crossover.

The two-night event saw the Arrowverse's heroes uniting for Barry and Iris' wedding, which was quickly crashed by a gang of Earth-X invaders. The altercation took our heroes on a world-hopping journey that none of them could have foreseen, and arguably changed the landscape of the fictional universe in the process.

"Crisis on Earth-X" brought fans new partnerships and pairings, heartbreaking moments, and some truly delightful action sequences. As some have argued, it shows just what the DC Comics world is capable of, and has changed the course for television events to come.