The Molodezhnaya is a more or less no frills hotel with clean rooms and more or less Soviet style decor and service to boot. It's in a totally non-descript part of the city - there's nothing to do here and nowhere to eat outside the hotel, but it's not too far from the center by Metro (about a ten minute walk from the hotel). If you speak some Russian and don't mind the commute, it might be a good choice if you're on a careful budget. Otherwise, there are other reasonable options a little closer in to the center.