My first choice is always the breed of dog I have at the moment which is long-haired chihuahuas. I fell in love with the puppy (Ricky) not the breed.
Our friends have a wonderful yellow lab named Seagram that is so sweet and gentle and lets the chi's cuddle up to him. He is getting old now and his hips don't always let him do the things he used to be able to do but he still likes to sit in the pool or lie on a rug next to a fire.
Remember, all dogs start off sweet and wonderful, how they end up depends on their owners.