A Golden is the best babysitter around, they'll keep the kids out of trouble and keep them amused as well.
My son's doctor has one in his office . . . for the kids to hug. Duke is an adorable dog and very gentle with the children. When I bring my Lab to visit him (they are madly in love) we have to turn them out in the back yard behind the office, because she is crazy and does her best to encourage him to be crazy too. But mostly she just runs and jumps in wild circles around him, while he trots sedately like a planet in his orbit.
My oldest two are 15 and 12, but neither likes dogs. And my 4-year-old would probably die of fright.
Golden retrievers are nice, though. We have one up the street who meets us on the sidewalk when we're out, and politely sniffs and wags.