Two of us will be in Rome Dec. 21 - 25 (ust can't resist those DL specials

).
Looking for a decent, moderately-priced hotel reasonably close to all the main tourist attractions, such as Colliseo, Forum, Piazza Venezia, Spanish steps, etc.
Any and all ideas are appreciated.
P.S. Is under $100/night price reasonable? How is Rome around Xmass? Busy or empty?