Rome - romantical suggestions for hotel?

[elportodelgato]

DH and I have somehow managed to wangle 4 nights in Rome sans kids! Very very excited and really want to make the most of it, so we're up for either a) a lovely boutique-y hotel or b) a brilliant, well-located self-catering apartment.
Does anyone have any tips on areas to aim for or great hotels / flats which we should look at?

Loved the Hotel di Ingalterra. What I call a proper hotel, and there are so few around. Not a whiff of executive corporate boring blandness. The location is fantastic, the lobby, restaurant, etc are ok but nothing special (for this, go and have dinner in the courtyard of Hotel de Russie), but the bedrooms are something else; very Italian, spacious, really nice antiques, lovely old fashioned bathroom, lots of windows. We were on a high floor in a corner bedroom and I could not tear myself away from the rooftop view, also loved having a bath, window open and shutters half closed, listening to the (somehow) elegant hum of the street bellow, Vespa noises...I LOVE Rome