In Stone Town, I recommend Tembo House Hotel. It is a three-star hotel and it offers a very good standard. It’s advantage is central location and it is directly by the sea, so you can enjoy your breakfast with your feet sinking in the sand. There’s also nice staff, really in this hotel you will feel like at home.
In Pwani Mchangani I can recommend Ocean Paradise Beach Resort and Spa. I had a half board, it was really good choice and the quality of food was very nice. The hotel garden is beautifully maintained. They have private part of the beach with sunbeds where the Beach Boys do not have access. The beautiful white sand beach further enhance your experience. It´s truly a paradise.

Ocean Paradise Hotel, Pwani Mchangani, Zanzibar