I chose girls...don't really know why, just thought they would be calmer. I think breed and genetics matter more than the sex. I correspond with many Golden Retriever owners, and it seems like there isn't a common thread. Some females are wild as bulls and some males as gentle as can be. You just don't ever know! If I have an opportunity to take in a rescue Golden, I will not worry about male or female, just whether the dog can exist with Honey and Lilly, the cats and us! Any pet I have will always be spayed anyway.
Good question, Jackie.