We have two dogs that I would call "medium" but most other people call "large". I love a dog you don't have to bend over to pet
. They are in no way giant like some of the dogs mentioned in this thread though.
Growing up, my parents bred large Dobermans. These dobes were BIG, way above standard. So, I spent most of my life thinking that dogs that could eat off the table without strain was normal.
DH's dad had a RR who also died of cancer... weird.
Both of our boys are mutts, and you can see them in the sig links. Samson is a Dalmation mix. We got him shortly after the movie 101 Dalmations came out (the "breeder" tied the purebreed mom outside and then dumped the mix puppies at the SPCA). He is about 75 to 80 pounds. He is 10 and a little over weight. Ralphie is a classic Yellow Dog mutt, also from the SPCA. His mom looked a lot like a shetland sheep dog and was about 35 pounds. So, we were surprised when Ralphie turned out to be as big as Samson (a little shorter though but less lean)! We suspect he is part collie, with some lab and GSD thrown in, and perhaps part something nordic.
DH wants a GD. I would love a wolfhound. But, like a previous poster said, we always have and always will Rescue, so the chances of us getting a purebreed are fairly slim. Plus, I would not adopt an adult large (or giant) dog, only a puppy, which limits us as to the purebreeds offered by many rescues. I do not have enough faith in my dog skills to re-hab a huge dog with issues, not with kids, other dogs and cats in the house anyway.