Na Rimskogo-Korsakova Hotel 

Hotel went through a recent remodeling, which still continues. so there is loud activity in the yard. I did not care about noise at all as they ceased working before I was coming back after a day in town. Another great thing is that hotel is located very close to center, its a 15-20 minute walk to the Hermitage, or a 10 minutes trolley ride. Taxi to the middle of the city is 150-200 rubles depending on the time of day. There is nice georgian restaurant right next to this place, and a nice cofee place just up the block (loved their kartoshkas). Now for the downside. They lock front door at 2am, so if you're going to see bridges opening - you have to enter through sorta back door, complex the first time unless someone actually shows it to you. There was no ac in my room, so we were forced to keep windows open and that invited lots of mosquitos, I had 3 bites on an elbow alone. But I still rate this place a 5 and would recommend it to anyone who does not feels like playing those $400+ per night in the middle of the city. I ended up paying 2 nights worth of hilton for the 5 nights here. The only way to get a better bang for the buck is to rent an appartment in the middle of the city, but that is next to impossible unless you are already in town. And, btw, this place fills up fast, so make sure to reserve early, and yes, they do charge extra depending on the number of people sleeping in the room (there is a russian law that dictates how big/small room has to be in order to accomodate 2,3,4, etc)