This is actually a more difficult question to answer than you might think, if you base it upon actual data and not just anecdotal evidence.
You must realize there is a difference in average lifespan, and the incidence of health problems, which might be bothersome or expensive to deal with, but which do not greatly affect longevity. For example, some of the smaller breeds might live quite a long time, but might have troublesome skin disorders or other problems.
Some of the working breeds are selected for vigor, speed, strength, or other qualities during their working lives, but may be prone to geriatric problems that have a later onset than during the prime working years. We really didn’t know about the high incidence of osteosarcoma in greyhounds before the popularity of retired racing greyhounds at pets, because they were so often dead before they were old enough to develop osteosarcoma. (Incidentally greyhounds are also prone to gastric torsion and cardiac problems as well as other health issues.)
Good data is surprisingly difficult to come by, at least in the US. Breed clubs do health/longevity surveys, but these are subject to various types of response bias.
One excellent source of information is the insurance companies in Scandinavia, where something like 90% of dogs - both purebred and mixed- have health insurance. One company, Agria, has compiled data on the longevity and incidence of various health issues and reasons for veterinary visits for all the breeds. I have the CD for Irish Wolfhounds and a few other breeds. Of course, it is possible that the gene pool of dogs from Sweden differs from the US, but it might be a good start for comparison.
The vet schools in the US compile data, but they are more likely to see the sick dogs in the population, and those owners who are willing to spend more money, so may not be truly representative, but that would be a start.
Anyway, if you are truly interested in an answer to this question, just be aware that finding the answer might be more complicated than you might at first think.