Skip the Line: Vatican Museums Walking Tour including Sistine Chapel, Raphael's Rooms and St Peter's
Tour guide was very knowledgable. I like the fact that the guides are Italian but have good English and really know their subjects. Most seem to have studied at University level. Obviously the Vatican museum is very crowded in summer months which is a little uncomfortably especially with children but the radio devices help you hear the guide well enough.
Loved this tour! Simon our very knowledgable and funny guide really brought the colosseum to life. Really good for children.