#4 The New Day (formed in 2014)

Members: Kofi Kingston, Big E., Xavier Woods
When, arguably, the most popular... thing... in pro wrestling of the past five or so years is only No.4 on this list, that says something.
Kofi Kingston, Big E. (and, at the time) Langston, and Xavier Woods were all (and still are) incredible talents that, in 2014, weren't really going anywhere. And then Woods came to Kofi and Big E. with a proposition (jump to 2:30 of this video)
So, that was actually interesting. A bit of a rehash of the Nation of Domination, but it's not like WWE hadn't rehashed worse idea before. But, after a short while, Xavier's vision became this:
When that didn't really work out, WWE did something unprecidented - they didn't give up on the team. Instead, they let the three men turn heel and control their own destinies. Soon, they were sprinkling pop culture references in their promos, wearing unicorn horns to the ring, and playing the fanfare from the Final Fantasy games after winning their matches.
When it started getting over huge, WWE quickly had them back as babyfaces, but still gave them the creative freedom that led them to success in the first place. Soon, they were breaking records as tag team champions and selling merch like hotcakes (in this case, almost literally). They even got their own breakfast cereal.
While they've had the most success in the tag team arena - including a WWE Tag Team Championship Reign of a record 483 days - they arguably had their greatest success in 2019, when Kofi Kingston defeated Daniel Bryan for the WWE Championship at WrestleMania 35.
Outside of the ring, Xavier Woods has a wildly successful YouTube video game channel, UpUpDownDown, currently sitting at over 2 million subscribers. The faction has also started their own podcast, The New Day: Feel The Power, where the guys discuss their experiences in the wrestling business.
Most of all, The New Day have shown what can happen when a company puts its faith in their talented performers.