Join Date: May 2011
Location: Northern California
Why not a Golden? If you buy from a reputable breeder, health issues will have been tested for, and I have met many, many Goldens happily in their teens. They are friendly, social, generally non-aggressive and can be very athletic (especially field-bred Goldens).
A well-bred Labrador kept lean will live a long time and be an awesome companion; friendly, biddable, athletic.
English Setters are wonderful companion dogs. Sweet, friendly, benign. The Llewellen type is probably going to be a bit more hardy than the show type.
Flat-Coated Retreiver is another good suggestion. They are a lot like Goldens, but if anything, they are a bit more Setter-like in disposition.
I have been looking at some of the recommendations here and I'm facepalming... Kuvasz? Giant Schnauzer? St. Bernard? Not what you are looking for. Avoid any type of livestock guardian (Kuvasz, Pyrenees, Maremma, Anatolian). They are not biddable at all, and some can be aggressive toward strangers/strange dogs. They are bred to be guardians and to think independently. I would also avoid Rotts and Giant Schnauzers as they have a tendency to be too guardy and a bit too much dog for what you need. St. Bernards are notoriously unhealthy and short-lived, as are most of the giant breeds.
I have not had good experiences with Swissies and Berners.
What you might consider is simply going down to the shelter and adopting a big black dog. Of course, you don't know how long the dog is going to live, but big black dogs are always the last to be adopted from shelters.