We stayed at the Riverview Hotel for 3 nights. I love the location of this hotel, the back entrance of the hotel is straight onto the rivers edge. There are a good range of restaurants along the river front and its a lovely area for walks in the morning. Walkways are well lit and the area (like most of Singapore) is very safe and clean.
Rooms are small but comfortable although there is a slight musty smell throughout the hallways. Rooms are quiet and there are kids channels on TV for rest time in the rooms. Beds are comfortable and bathrooms are clean.
Room service is prompt but pricey and the restaurant on the ground floor has basic meals like burgers as well as buffet meals and coffees and cakes.
Inexpensive river taxis are located right at the back of the hotel and are a convenient mode of transport. Buses to the zoo pick up and drop off across the road (straight over the overpass.)
The Riverview Hotel is not a bad option if you can get a good deal.