I watched Ted 2 yesterday with three of my children (aged between 13 and 26) and basically we laughed and giggled non-stop for the whole two hours. We chose the 'unrated' version rather than the 'theatrical' version, I don't know if the theatrical version was as good - if you cut out all the swearing, you'd only have about ten minutes of footage left.
It helps if you've seen the first one I suppose, it might not make quite as much sense on its own. Apart from that, I shall not bother summarising the plot or the characters or anything, it is what it is.
Ten out ten.