Every Arrowverse Crossover, Ranked

12. "All Star Team Up"

Every list has to have to have an entry at the bottom and that space on ours is occupied by "All Star Team Up," the 18th episode of The Flash's first season.

The episode saw Arrow's Felicity Smoak (Emily Bett Rickards) and Ray Palmer/The Atom (Brandon Routh) pay Team Flash a visit because Ray needed help with his suit. As luck would have it, Team Flash finds themselves dealing with the villainous Brie Larvan (Emily Kinney) unleashing hundreds of robotic bees against her fomer co-workers. The overall lackluster episode also featured a really awkward dinner between Barry, Felicity, Ray, Iris (Candice Patton) and Eddie (Rick Cosnett) that just made things uncomfortable all around.

11. "Heroes Join Forces"

The second official Arrowverse crossover, "Heroes Join Forces," saw the Flash (Grant Gustin) and Green Arrow (Stephen Amell) come together to take on the villain Vandal Savage who is looking for Kendra Saunders (Ciara Renee) and Carter Hall (Falk Hentschel), the reincarnations of Hawkgirl and Hawkman.

The crossover largely was used to set the stage for DC's Legends of Tomorrow, which was at the time being developed as a spin-off series as Legends would heavily feature the newly formed team's fight against Savage during its first season. While the crossover generally received positive reviews, the set up for Legends was one that many fans found to be problematic and it's that complaint that lands "Heroes Join Forces" near the bottom of our list.

10. "Girls Night Out"

The fifth episode of The Flash's fourth season, "Girls Night Out" had a ton of potential. Caitlin (Danielle Panabaker,) Cecile (Danielle Nicolet) and Felicity (Emily Bett Rickards) join Iris (Candice Patton) for a pretty chill bachelorette dinner and night out. Of course, nothing goes that smoothly in the Arrowverse and the evening ended up seeing the ladies face off with Amunet Black (Katee Sackhoff).

While it was nice to see the ladies take center stage and kick some bad guy butt, the episode was just okay and, for an episode where the ladies were meant to take center stage, some of the best scenes belonged to a very drunk Barry (Grant Gustin) expressing his love of chicken wings.

9. "King Shark"

King Shark escaped his A.R.G.U.S. holding tank in the episode of the same name during The Flash's second season, prompting Arrow's Diggle (David Ramsey) and Lyla (Audrey Marie Anderson) to head to Central City to warn Team Flash. King Shark tracks Barry to his house, Team Flash tries to trick King Shark into a trap, they fail, and eventually Barry is able to subdue the villain with an electrified underwater cyclone.

Yeah, that's about it. It was just as dry on screen as it is in that brief recap landing it at number 9 on the list. It beats out "Girls Night Out" only because, c'mon. King Shark.

8. "Invasion!"

The third Arrowverse crossover, Invasion! was the biggest yet at that time as it incorporated not just Team Flash and Team Arrow, but the Legends and even Supergirl got to come out and play.

While the story overall -- a loose adaptation of the 1989 Invasion! miniseries -- wasn't that great, the series included Arrow's 100th episode which saw Team Arrow abducted by Dominators and, via mind control, given a glimpse of a life that could have been in a truly beautiful, haunting episode that elevated the entire crossover.

There's also a great line from Brandon Routh slyly acknowleding his time as Superman on the big screen that is just gold.

7. "Going Rogue"

The fourth episode of The Flash's first season "Going Rogue" saw Felicity Smoak pay a visit to Barry after hearing all about his new speedster abilities. With Felicity and Oliver not yet a thing and Iris firmly with Eddie at this point in the story. Barry and Felicity even share a sweet kiss.

The episode also sees the introduction of Leonard Snart/Captain Cold (Wentworth Miller) and Mick Rory/Heatwave (Dominic Purcell) which is part of what makes this episode so great as both characters end up on Legends of Tomorrow.

6. "Star City 2046"

During the first season of Legends of Tomorrow, the Waverider malfunctions and crashes in a bleak future Star City -- Star City 2046 to be exact. The episode saw the team discover a city overrun by criminals as well as a grizzled, bitter Oliver Queen among other revelations.
As crossover episodes go, at the time this was a pretty average to even below average one. However, the episode has started to take on a bit more meaning now that, in Arrow's seventh season, we're getting additional glimpses of a devastated future Star City, one that's starting to look an awful lot like this nightmare future dystopia come true.

5. "World's Finest"

While Supergirl has been on The CW for three seasons now, the series started out on CBS which is part of what places "Worlds Finest" so high on our list. The episode -- the 18th for Supergirl -- sees The Flash's Barry Allen jump not only Earth's but networks as well.

Barry, while testing a tachyon device, literally runs to Earth-38 where he meets Supergirl/Kara Danvers (Melissa Benoist). The pair defeat the villains Livewire and Silver Banshee. The two heroes even race one another to facilitate Barry getting back to Earth-1. The whole episode is delightful, but more than that, welcomes Supergirl into the Arrowverse before the series moved to The CW for its second season.

4. "Duet"

Coming in at number 4 on our list is another Supergirl/The Flash crossover, this one taking place in Central City. The seventeenth episode of The Flash's third season, "Duet" takes advantage of the cast's musical chops when Music Meister (Darren Criss) traps the two heroes in a coma that, in turn, traps them in a musical.

There's singing, dancing, a great gangster plotline, and in the end both Barry and Kara come to realize the love in their lives in the process -- which was Music Meister's entire goal. While the episode is a little bit unusual for a superhero world, it's got some great moments -- we dare you not to sing along to "Super Friend".

3. "Flash vs. Arrow"

Number three on our list is the OG Arrowverse crossover, "Flash vs. Arrow".

The episode sees the two teams come together to take on villians in both Central City and Starling City, but it's not the villains or the fights that make this episode so noteworthy. It's seeing Barry and Oliver start to try to understand one another and learn about each other's differences -- and similarities -- in the process. The crossover sets the stage for all of the future team ups in the Arrowverse and even gets referenced in this year's "Elseworlds".

2. "Elseworlds"

Speaking of "Elseworlds," it takes the second spot on our list.

We won't get into too much detail about it since it's still pretty fresh in our memory but "Elseworlds" was truly epic event. Legends of Tomorrow largely sat this one out (Gary did make a fun cameo appearance) but it saw the introduction of Ruby Rose as Kate Kane/Batwoman, John Wesley Shipp reprise his role as 90s Flash, and it was full of clever, funny Easter Eggs. The best part, though? "Elseworlds" sets up a lot for next fall's "Crisis on Infinite Earths" and we can't wait.

1."Crisis on Earth-X"

While "Elseworlds" was big and wild and interesting, we had to give our top spot to "Crisis on Earth-X". Last year's event was an intense, complex story that not only felt big in terms of scale, but also in terms of emotional stakes for all of the characters -- both those of the Arrowverse we know and love, but for the Nazi world Earth-X. It also contained one of the most heartbreaking moments in Arrowverse history: the death of Professor Martin Stein, one-half of Legends of Tomorrow's Firestorm. It was a terrible loss for the team, one that would have deep ramifications for Legends going forward. The fact that the crossover ultimately ended with weddings for Iris and Barry as well as Oliver and Felicity is really only an afterthought when compared to the deeply emotional loss of Stein.

Do you agree with our rankings? Let us know in the comments below!