I've been on a few tours with Gap, and they have been excellent fun-filled adventures off the beaten path.
In Italy, our guide was Fabio, who was just wonderful. He made the Italy experience unforgettable. In Peru, although it was a very tiny group, we still had a guide who made it almost a private tour. (Only later did we find out that they whole time he was using a derogatory term to refer to us, but hey, that was on the last day. :)). We've also gone to Costa Rica with them.
A rival company, Intrepid, does the exact same tours, sometimes maybe in a reverse direction.
I would recommend GAP for the inventive tours. Just be very careful with the guides. They can make or break it. read more