Amazing Gelato--Possibly the best ice cream in Rome, and ice cream is one of the few foods that still exceed expectations in Rome. I ate Kentucky chocolate tobacco, which sounds disgusting but was rich, dense, and delicious.
Go to Rome. Go to Giolitti. Order a cone w/ a scoop of chocolate and a scoop of hazelnut. Go crazy and add some whipped cream. Wander the beautiful streets with your treat. Congratulations, your life is complete.