Year in review: 2015 most viral videos

From the famous to the infamous, the hilarious to the heart wrenching and the adorable to the infuriating. Seriously, what color is that dress? This year was chock-full of viral moments.

Seven-year-old Dylan Barnes shook it off this year, dancing his way onto 'Ellen' and into the presence of Taylor Swift herself. Barnes got to meet the superstar backstage at her tour stop in Kansas City and they had an epic dance-off.

The future arrived in 2015, at least in "Back To The Future Part 2" terms. On Oct. 21, the world paused to geek out over the day the 1989 movie named "the future"-- a world of flying cars, hoverboards and holograms.

The whole thing culminated with the actors showing up on prime time in none other than The Delorean.

There was perhaps no viral video in 2015 as horrifying as when a vehicle's dash camera captured a Transasia flight as it careened out of the sky, clipped a vehicle on a bridge and plunged into a river.

Officials said pilot error was to blame. Forty-three people were killed.

Pharmaceutical CEO Martin Shkreli made headlines when he raised the price of a life-saving AIDS medication. The increase wasn't just a couple of bucks, Daraprim skyrocketed overnight from $13.50 to $750 per pill.

The Daily Beast declared Shkreli "the most-hated man in America," surpassing even the dentist who killed Cecil the Lion.

Speaking of...Zimbabwe's prized "Cecil the Lion" was illegally hunted in July sparking an international firestorm against Walter Palmer. While Palmer didn't face charges, he did face abject humiliation. The controversy even inspired ridiculous Halloween costumes.

A Patti Labelle fan's ode to the singer's frozen dessert pies sent sales through the roof when his musical review went viral and captured the attention of the singer herself.

Labelle made sure the fan got his just desserts, hosting him for Thanksgiving dinner.

From one diva to another, Johanna Colon channeled the essence of Aretha during a summer dance recital. The sassy 6-year-old tapped her way to total stage dominance.

It was a story that had everyone talking this year-- the dress! Is it blue and black or white and gold?

It was a question that sparked countless Buzzfeed articles and threatened to tear families apart.

For the record, it's totally blue and black.