No, it's not Bud Light's Spuds Fucking Mackenzie.
Nor is it Gidget, the Taco Bell Chihuahua.
Campaign UK is currently holding a poll to determine the greatest ever ad featuring a dog. They list 10 spots, most of them superb.
I've taken the best of their list, and added a couple of my favorites from recent years.
I've picked my winner.
Now it's you turn.
Harvey for Thinkbox
The dog's real name is Sykes. He's a Terrier from Oxfordshire, where he was found as a stray. He's now world famous, thanks to advertising. He's the official spokes-dog for Thinkbox, marketing arm of the UK's commercial TV broadcasters.
Here's two of his commercials for Thinkbox.