Hi, 1mtamayo. We spent 8 days in Rome earlier this summer. Since my husband had never been to Rome and I hadn't been in about 40 years, we started off by taking tours of all the big sites. Then we started on other activities. We had a blast on a Rome Food Tour conducted by Walks of Italy, which was recommended by Rick Steves in his guidebook. The tour started at the Campo de Fiori market where we tasted olive oils and balsamic vinegars of all varieties and ages. We also tasted some of the liqueurs which Italy is famous for. We visited a meat market and cheese shop. Then we walked a short distance to a restaurant where we were taught how to make our own pizza. I put eggplant and zucchini on mine and it was yummy. We felt really immersed in the Italian way of life.
Although the double decker bus tours are not highly recommended, we decided to take one anyway and really enjoyed it. We also enjoyed taking the tiny electric bus (that we caught about a block from the Grand Flora) which runs in areas the larger buses can't go in.
We enjoyed a half-day tour to Ostia Antiqua. The guide meets you at the train station and accompanies you to the site. The tour was wonderful. After the tour, you can return to Rome with the guide or head to the beach in the other direction.
We also found a delightful sandwich shop between the Trevi Fountain and the Spanish Steps. It is called La Sandwicheria and is located at Largo del Nazareno, 16/17 00187 Roma. It is a little difficult to find, but well worth the journey. Their website is lasandwicheria.it. It is in Italian, but be sure and look at the gallery of pictures. The sandwiches were delicious. My favorite sandwich was the eggplant/mozzarell/tomato on toasted ciabatta bread. Yummy! It's less crowded early or late. I highly recommend it.