The CW's Crisis on Earth-X crossover event – featuring Arrow, Supergirl, The Flash and Legends of Tomorrow – was a better team-up than Warner Bros. and DC Films' Justice League. Ever since The CW expanded its comic book TV universe to include The Flash, a spinoff from the network's flagship DC series Arrow, they've aired annual crossover events. While the first year only featured a team-up between the Green Arrow and the Flash, these events have grown exponentially to include heroes from Supergirl and Legends of Tomorrow. This year's crossover event, Crisis on Earth-X, was the biggest yet to air on The CW with the heroes facing off against Nazi versions of themselves from an alternate universe.

Because The CW typically airs its crossovers at the end of November, Crisis on Earth-X debuted only 10 days after Warner Bros. and DC Films' premiered their own massive team-up event with Justice League. While the reviews for Justice League were undoubtedly an improvement upon previous DC Films entries Batman V Superman: Dawn of Justice and Suicide Squad - and the film topped the domestic box office in its opening weekend and performed well overseas - the dominant narrative has been that it didn't quite meet expectations. Certainly, the movie has its fans, and redeeming qualities, but Justice League wasn't as big of a success - critically, financially, or with fans - as many were hoping.

Related: Justice League Should Have Been More Like Batman V Superman

Crisis on Earth-X, however, was undoubtedly a hit with critics and fans. Though The CW's crossover episodes aren't necessarily the best each show has to offer in terms of story, well-developed villains, or compelling character arcs, they're often beloved by fans because, at the end of the day, they're made for the fans. The annual crossover events are often the height of comic book fun in the Arrowverse, with the TV superheroes uniting to take on a threat pulled right from the comics. With Crisis on Earth-X going bigger than ever before, The CW was able to deliver even more comic book fun. Ultimately, though Crisis on Earth-X and Justice League are two DC Comics events that were aiming to do different things across different platforms, the Arrowverse crossover was better than the highly anticipated big-screen team-up of the World's Finest heroes.

Perhaps the biggest point of contention, and the biggest criticism, plaguing Justice League is that it feels like the product of two directors - which, of course, it is. Though Justice League was meant to be the capper in Zack Snyder's DC Films trilogy that began with Man of Steel and continued through Batman V Superman, the director stepped away from the project due to a personal tragedy. After reports that an early cut of Justice League was "unwatchable," Warner Bros. brought in Joss Whedon to helm reshoots, though he'd already done some work on the script.

The resulting movie isn't quite Snyder's vision - which has prompted petitions for Warner Bros. to release a Snyder cut of Justice League - but isn't quite a Whedon film either. That lack of consistency means fans of Snyder's work, though they may be in the minority, were underwhelmed by the film, while those hoping Justice League would be a massive overhaul of the DC Films universe also didn't entirely get what they wanted either. The competing visions of Snyder and Whedon/Warner Bros. were felt by many who have seen Justice League, and lessen the experience of the movie - perhaps more for some than others.

Related: The DC Movie Universe is Worse Without Zack Snyder

Meanwhile, The CW's Arrowverse crossover this year had perhaps the most consistency of any of the network's crossover events. In previous years it's been abundantly clear which larger series each section of the crossovers have belonged to, for better or worse - though usually for worse. This year, however, Crisis on Earth-X had the most consistency in tone and story across the board of all four of The CW's DC series. Certainly, there was still some differentiation in tone between Supergirl and Arrow on night one, and it was clear which episode was Legend of Tomorrow's since the remainder of the team suddenly appeared.

That said, the creative teams behind all four series worked together to make Crisis on Earth-X feel like a four-hour movie spanning two nights, and they undoubtedly achieved that feat with more consistency than fans may have expected. Of course, their additional two hours of runtime (give or take commercials) compared to Justice League undoubtedly helped Crisis on Earth-X as the Arrowverse could introduce and explore multiple character arcs across the event - and continue arcs from the four CW series.

The creative teams behind The CW's DC shows have continually pushed themselves to exceed expectations each year and do something they've never done before - and something no other superhero TV series has done before. The result is that each Arrowverse crossover feels fresh and new. While there are undoubtedly certain connective threads that weave through each event, the different villains and storylines push the envelopes of each series in the shared TV universe. The Arrowverse shows can sometimes get stuck in ruts, with the shows arguably reusing similar villains or storylines, even with only a handful of seasons under their belts in some cases. But, the crossovers continue to evolve and force The CW's DC lineup to mix things up in a way that feels fresh, while not messing with the core DNA of any series.

In comparison, some have accused Justice League of copying Marvel's The Avengers a bit too closely. Of course, both movies follow a similar basic structure with certain heroes trying to recruit others to a team in order to fight an invading alien who wants to conquer the Earth, only for them to realize the importance of teamwork and unite to ultimately defeat the threat. While the highly anticipated uniting of DC's biggest heroes in live-action for the first time is momentous, the story of Justice League left a great deal to be desired. In the five years since The Avengers debuted, it's not unreasonable to think superhero movies have evolved and fans expect more than what amounts to a movie essentially resting on the excitement for, simply, superheroes teaming up.

Related: All The Similarities Between Avengers and Justice League

Not only have we gotten two Avengers movies in the last five years, The CW has aired yearly crossover events since 2014, and Netflix even debuted their own small screen superhero team-up this summer with The Defenders. Ultimately, the team-up aspect of Justice League is something comic book TV and film fans have seen many times now, though not necessarily with these exact characters. While there's undoubtedly excitement each time a team-up event occurs in either film or TV, Justice League simply using different heroes in a story we've seen before - even though they're unquestionably some of the most beloved and storied heroes in comics - isn't quite enough anymore.

Of course, it's also possible that The CW's "Crisis on Earth-X" is a little fatigued by viewers tired by either superhero content on the whole, or comic book media that feels too similar to something else. This year's event couldn't top the ratings of the 2016 Arrowverse crossover, and according to TVLine, only averaged 2.7 million viewers/0.9 rating compared to last year's 3.7 million/1.3 rating - though those numbers could change as fans tune into the shows on streaming services in the coming week. Undoubtedly, though, more people went to theaters to see Justice League than tuned into The CW to watch Crisis on Earth-X.

Certainly, at the end of the day, movie and TV viewers can - and should - like what they like. In terms of which event, either Justice League or Crisis on Earth-X, was more successful in achieving what they set out to do, however, the Arrowverse crossover clearly pulls ahead. It's much more consistent in tone than Justice League, a surprising feat given it unites four different TV shows, and ups The CW's superhero game, improving upon crossovers that came before it. All in all, Crisis on Earth-X is a better, more cohesive team-up event than Justice League.

Next: Crisis on Earth-X May Reshape How The CW Handles Future Crossover Events