I spent, sorry "wasted", my two days in this city. I didn't visit any museum due to both limited-time and money factors. As far as I'm concerned there is nothing to see in this city except Vatican and Collesium. Worst metro line I've ever seen. I don't get why people are so crazy about this city. The streets were full of rats and the smell of urine. Almost every metropolis cities have urine-smell but Rome's was significant! And also drivers were crazy. I recommend İstanbul, definitely!
Insider Tip:Every sunday of each month, there is free entrance to Colessium. If you'll visit Italy on December be sure to check the places on which restoration process so that at least "you" can see the "Fontana di Trevi" :(