Rome is one of those super popular places that you must visit but have a hard time finding a hotel which is at the same time really nice but not too overpriced. In Paris I always stay in Hotel Grands Hommes which I love but which has become way too overpriced. In Rome I found such a hotel on my second try and this hotel is the Venezia Hotel. Unless it gets overpriced I will always stay here when visiting Rome from now on. My first hotel was Hotel Gallia a few blocks on the other side of the central station, but I didn't really like it that much. Why Venezia hotel:
(1) A few steps from the train station so whether you come to and leave Rome by train or by train from and to the airport you are right there, no taxi, no walking, very convenient.
(2) Rooms are very nicely designed, very modern, clean, bright, do not feel cheap at all. It might be a little small, and in our room the shower and bathroom where in two different rooms on different sides of the bed, but very nice overall. The bed was comfortable and new. Our room was not facing the street but in any case the area is quiet, the small streets in front of the hotel have almost no traffic.
(3) The breakfast in very nice, good selection of hams and cheeses, nice pastries, a couple of delicious tarts every morning, some nice hot dishes, like eggs and sausages, very good fruits, juices, etc. Servers are busy asking what kind of coffee you would like, so we could enjoy two cups of cappuccino during our breakfast. The breakfast area is a little small so it might get somewhat packed but it did not spoil the enjoyment of a nice breakfast, nice service, and a very pleasant cheerful attitude of the servers.
(4) Close to Rome University so you can find many nice restaurants within walking distance, especially south of Via del Ramni, as well as many nice cafes, especially around daily market on via Montebello. In fact, Trattoria Varesino right near the entrance to the hotel is very very nice, not fancy but great home cooking with very cheap and tasty house vines. The owner, who is always there, is a grumpy old man, but his son is really running the show and he is very nice. Do not pay attention to the mean acting grandpa and enjoy a really nice food. I saw only local people eating there, no tourists at all.

Final thoughts. You might be tempted to stay in a nice "name" hotel closer to Coliseum and Forum area, or Vatican. Well, I would save my money for a nice romantic city like Florence, or Venice, or Amsterdam, or even Paris to splash on a nice fancy hotel. As a city, Rome is rather unattractive, too big and dirty. You come to Rome for its attractions and not for the city itself. In hotel Venezia we could walk to the central station, and easily take a subway to all the attractions from there. Once you are done enjoying those impressive sights, hotel Venezia is a nice place to relax and enjoy the rest of your day.