Great Danes. Mine bark when they hear something out of sorts. It's a big booming heavy bark and most people that come to the door step back up 2 or 3 steps just when they hear the bark. They back up more when the dogs come to the door and are eye to eye with them. As companions you couldn't ask for more loyal loving dogs. But being a large breed the vet bills are higher and transport and general care requires a bigger vehicle and more time. I would do some heavy research in any breed you select so you get one that fits you best.
"I can neither confirm or deny, nor do I wish to speculate at this time, or in the future." -What to say when your wife asks if she's getting fat.