I have been the proud owner of many dogs. When I was younger I had bigger dogs, but now I own a couple of little ones. Both are great but they both have pros and cons to owning them. I hope that you tell me your preference in the comments below.
Big dogs can be very playful and fun but are not always the best. They can be great for kids as long as they are trained well. In my experience big hounds are easier to train and are more likely stay on their bed and not on yours. They are usually more friendly than smaller dogs and bite much less. They shed much more and there are very few large dog breeds that don't shed. If you do get a large canine you should keep them from jumping up on people and licking them or even knocking them down. A bigger pooch can be trained to be rescue or guard dogs and they do better at it then smaller breeds. The worst thing about big dogs is how much they shed and slobber. Larger canines are great for smaller families or families with older children.
This is my dog Max.
Small dogs are very nice and many breeds don't shed and they are very friendly to their owners. From my time with Max he is much more defensive then larger of his species I have owned. Smaller pups tend to require more attention than larger ones, but not as much exercise. Little fido may be nice to you but it comes with a cost. Max has been sick much more than my larger pups were and vomits a little more easily. One of the best things about them is how loyal and nice they are to their trainer. I don't like the amount of attention they need. Small canines live much longer and require much less work overall. Different dogs are for different people but I prefer small ones to large ones. They are better for families with younger children or single people.