YouTube ranked UK ads on its platform this year based on factors including views, how long people watched an ad for, and the proportion of organic views compared to paid views.
The "baby & me" video, created by BETC Paris for Evian, took the top spot. The film, which launched in April, featured the bottled water brand's trademark babies dancing to the Ini Kamoze song 'Here Comes the Hotstepper', remixed by Yuksek.
In the ad, adults catch sight of baby versions of themselves in mirrors and start dancing with their younger counterparts, tapping into Evian's 'Live Young' brand tagline.
The Evian ad spawned 334 viewer-created versions and more than 6.9 million people shared the video on social networks.
John Lewis' Christmas ad, "the bear and the hare", which was released last month, followed in second place.
The animated spot was created by Adam & Eve/DDB and has had more than double the number of YouTube views of last year's "the journey" ad, also by Adam & Eve/DDB.
In third position was "the pony" by Wieden & Kennedy, the moonwalking pony animation for the mobile network Three.
The top-ten ads had more than 180 million views between them in the UK this year, including paid-for views and organic views.
YouTube UK ads leaderboard 2013
1. Evian "baby & me" by BETC Paris
2. John Lewis "the bear & the hare" by Adam & Eve DDB
3. Three "the pony" by Wieden & Kennedy London
4. Dove "real beauty sketches" by Ogilvy & Mather Brasil
5. O2 "be more dog" by VCCP
6. Honda "hands" by Wieden & Kennedy London
7. PlayStation 4 "see it first at E3" teaser by Sony PlayStation
8. Pepsi Max "bus levitation" with Dynamo by Arnold KLP
9. Fifa 14 "we are Fifa 14" by Wieden & Kennedy Amsterdam
10. Sony "sound, vision, colour, detail" by McCann London