Iwent a good few years ago and there are lots of things to see . How long are you in Rome for ?
Lets start with St Peter's Basillica. Biiggest church in the world. The Vatican . The Colusseum . Trevi fountain . The Spanish Steps .The Roman Forum . The Apian Way . Try a trip down the Catacombs . The Castle De Saint Angelo . The Pantheon . The Vittorio Emanuele Monument . The Piazza Navona .
You will need at least 5 days . . . and lots of money because it isn't cheap .
Have a great time .
Take some comfortable walking shoes as there is so much to see - stunning architecture around every corner.
We found that the further away from the station you are, the cheaper prices got. We stayed in The City Hotel (wonder why I picked that) which was cheap and cheerful and a 20 min underground trip away from the centre. It was in a residential area so the local restaurants were much cheaper but just as good quality. The underground system is very good.