Alternately, if you had a choice at a Rescue center and one of the choices was a Golden Retriever, you couldn't go wrong.
They have a wonderful tempermnet, are quite obedient and, if you could know the lineage, they can be medium sized... certainly a little smaller than the faithful Lab. Some can be quite large though. If it's still a puppy, inspect the feet... large puppy feet equate to large adult dog.
Only difficulty with the Golden (Seen here:
http://www.akc.org/breeds/golden_retriever/photos.cfm) is some skin conditions, including an undercoat that, while making them love the snow, needs to be brushed at least once a month. Some shedding, of course.
Wonderful with children, even babies and soon become protective but not aggressive. Easily trained to obedience, they are excellent companion dogs,
As to the mix breeds... I've personally found them to often be tempermental. A good thing is that they are hypoallergenic and as such, tends to shed very little. They can be largish. A neighbor has a 4 year old bitch and she's larger than the usual Golden. She requires trimming at the groomers nearly once a month. Somewhat reticient in behavior. They have two boys in the family ... 9 and 12. She'll sit outside in all kinds of weather... -20 F with 2 feet of snow and wait for them to come home from school on the bus. She avoids visitors and isn't comfortable with outsiders...