I've done the World Showcase tour (Hidden Treasures) and liked it quite a bit. Also liked Backstage Magic, and Yuletide Magic (which, not too surprising is only available between Thanksgiving and Christmas). I would do any of the three again. For the World Showcase tour, it was a 'flex feature' on our package (so that tells you it was a while ago), Backstage Magic we had a discount (I think it was Magic Kingdom Club) and for Yuletide used the Disney Visa discount.
Yuletide was fairly interactive with the CMs sharing personal stories and asking the group about their family traditions, which I thought was nice, but also tended to create an overtime situation, though they did ask going in if anyone had lunch plans. Neither Backstage or Yuletide required park admission, which is another bonus if you've got some other plans for the rest of the day.