If you visit Rome, make sure to visit the Capitoline Museum. It has a room it calls the "Hall of the Emperors" containing busts of so many emperors. I was able to recognize many of the busts as the main ones used on Wikipedia, here, and all over the Internet. It was surprising how many of them were all there in one room.
I went there in 2016, and unfortunately the room was under renovation at the time. There was still a myriad of other iconic sculptures to see in the museum though!