We went with a group in 2009. We loved all four basilicas (St. Peter's, St. John Lateran, St. Mary Major, and St. Paul Outside the Walls) and also the Pantheon, the Roman ruins, and the catacombs! Don't miss those. We went to the catacombs of St. Callixtus. Also, Soprani's is a store near St. Peter's Basilica that sells inexpensive religious items.