Although it depends on the age of the children, which you fail to mention, I think it is true that some dogs are naturally better. By instinct you should avoid large boisterous breeds such as bullmastiffs or German Shepherds, although if your kids are older these may be ideal. Small or miniature dogs are usually a fairly safe bet, although some can take quite exception to the constant attention paid by inquisitive youngsters. I would personally recommend a Golden Retriever or Black Labrador. These are highly intelligent, placid creatures which always seem to have a smile on their face and love doing things in the garden or going on vacation.