Having a dog has been a fun and wonderful experience for everyone in your family. In fact, it has been so rewarding that you are now seriously thinking of getting a second dog. However, it is important that you really think this decision through, because having two dogs can be an entirely different experience from having one.
For the health and wellbeing of your dog, training should really not ever be considered an option when owning a dog. Well trained dogs are more likely to be behaved and listen, be void of behavioral issues, be good in public, and are less likely to bite. Owners also have a much closer connection with the dog when the time is taken to form a relationship through training.
If you ever owned a dog when you were a child, you can probably recall the joy and exhilaration you felt every day, playing with your best buddy. Once you grew up and (assuming you) started a family, you probably wanted your kid(s) to experience the same things that you did. A loving, loyal, fun-loving animal companion is one of the best things in the world.