If you are wanting to stay at a full-service, Hilton branded hotel property while in Rome without…read moregoing bankrupt doing so, The Doubletree Hotel by Hilton Rome Monti would be a solid choice. By Rome standards for a full-service hotel, it would be considered affordable by many. But just to be clear, it is not ultra-inexpensive.
For the money, it is firmly in the 4-star hotel genre (getting a 5-star Yelp rating from me within this category because I could find nothing wrong with it during my stay). So, while it may not have crystal chandeliers and butlers running around, it is definitely not a student tourist level hostel. It has modern, comfortable public spaces, elevators that hold more than 2 people at a time, a restaurant with a good breakfast spread, and well-appointed guest rooms with modern amenities and AC. I really don't need more than that when I am traveling solo for business so it was perfect for me given that set of circumstances. As a comparison, I have stayed at a 5-star Rome hotel which was absolutely a step up in terms of service, luxury features, and a sense of a personal attention. But when I am alone on business, that level of service is not necessary and can feel uncomfortable to me.
There are plenty of cafe's and restaurants within a 10 min walk and it is a reasonable walk to attractions such as the Opera House, the Coliseum, and the Trevi Fountain. It is also a 10-minute walk to the main terminal Rome train station and the cool, local Nuovo Mercato Esquilino if you are into that type of thing like I am. I spent early mornings walking somewhere for coffee and then through the Mercato to watch the vendors work to ready their produce and meat to be pawed over by early restauranteurs which was a cool look at the underbelly life of this great city.
I really liked that this hotel is not right up against the busy street and, on at least 2 sides of the building, there are streets that are not constantly jammed with the noise of traffic. My room fronted one of the quiet sides. It is unclear to me if I was upgraded to a nicer than standard room location because of my Hilton loyalty status but I had a very quiet stay in a room that was impeccably clean and could be easily darked out during the day if I needed a restorative nap for my jet lag. The gym was reasonably appointed and open 24/7 and the wi-fi speed was top notch. I had a great stay here for the money.
Based on all of this, when in Rome in the future as a solo business traveler, I would be very happy to stay here again.