Rome wasn't built in a day, nor should you tour it in as much. Those I know who have done "daytrips" to Rome didn't like it...You have to digest the city for a few days before you grow to love it. It is definitely worth it.

Pantheon, 119-128 AD.

Trevi Fountain.

The Roman Forum.

Modern day Gladiators.

The Crypt of Capuchins, a monks cemetery.

Piazza Navona.

Spanish Steps.