Some of the hunting breeds, sighthounds and setters mainly, can be pretty laid back. With most sighthounds they need a few minutes a day running like crazy full bore, and they're on the couch the rest of the time. Retired racing greyhounds can be great pets for lazy owners so long as they have a fenced yard or nearby park where the dog can run for a few minutes.
Bulldogs are about as lazy as it gets, but loads of health problems.
Getting into the really big breeds, Danes and most of the mastiffs are very laid back and lazy too. Most American line Dobermans I've met are as well.