I'm not sure what mine is. Common consensus is an American Pit - American Bulldog mix. But he gets along perfect with my 3 year old. He is very protective and let's my son rough house with him all day long. Never a hint of aggression or a single problem ever. In fact quite the opposite, this dog has made it very clear he would take a bullet for my son if he needed too. Just the other day he protected my son from a rattlesnake we ran into while hiking. He put himself between my son said snake. Don't get me wrong it wasn't a close call or anything, but I was very impressed with my dogs behavior is all I'm saying. He saw possible danger and reacted perfectly. I really love this dog and he is a great member of the family.
Here's a vid of him playing with my son.
YouTube - Josh, Atlas, And bubbles
And here is a vid of him hanging out with my girlfriends kids who he has just met. You can see that even though it's very difficult for him to do so he still follows them through any condition.
YouTube - Atlas hanging out with the kids
My brother has a boxer and she is fabulous. Very good family dog, medium sized and short hair. You might want to look into those too, although I could not find any in the local rescues and shelters I looked in. My friend has some rottweilers, and they might be too big for what you are looking for but are also excellent. And last but not least, I have run into some whippets that I would totally be down with owning. Although they might require too much exercise depending on your activity level. You might just get in touch with a couple rescue groups and tell them what you are looking for, then they can introduce you to some possible candidates. That's what I did and I ran into a lady who got me EXACTLY what I wanted. Not sure if all of the rescue groups are that way, but I was very impressed with the one in my area. I would never have considered getting a pitbull because of the stigma attached to them, but it's the best dog I've ever owned. She was right.
While we are on the subject, here is the absolute WORST dog I ever owned. Do not get one of these and put it around a child, ever..... Mini Dachshund. It's cute but has the worst personality of any breed I have ever seen regarding children.
This is the meanest most aggressive dog I have ever owned and sadly the most expensive. It started growling, niping, and then lunging at my son when he started crawling. I thought I finally had it under control, then one day he bit my son on the finger for pretty much no reason and no warning. Didn't draw blood, but made him cry. Took soo much effort not to punt the dog across the room when that happened. Got rid of him immediately though.:madgo: