Chios has a large number of hotels of all different catagories as well as rooms to rent. Its just a matter of deciding where you want to stay.
In Chios-town I stayed at the Chandris Hotel which is probably about as good as it gets, at least in town. Terrific view, nice breakfast, a pool, Greek music nights on Friday with a buffet dinner,
good air-conditioning and within walking distance of just about anywhere in town.
Nearby is the Grecian Castle Hotel offers year-round accommodations in elegant rooms at pretty reasonable prices in a large mansion with a swimming pool, right on the sea. For more economical accommodations try the 2-star Diana Hotel on the waterfront which has a roof garden with views of the Aegean Sea and a snack bar. It offers air-conditioned rooms with free Wi-Fi. Porto Chios Hotel is within a short walk from the port, the castle and commercial shopping and offers tastefully furnished accommodations with free Wi-Fi and a private balcony. If you want to be close to the ferry Aegean Sea Rooms offers tasteful accommodations with free Wi-Fi access.
In Campos the Argentikon Luxury Suites have been recognized as one of the 100 Best Villas in the World I guess by Conde Naste or one of those kinds of magazines or maybe it's a club or something. Regardless, it is hard to doubt that it is one of the 100 best villas, hotels or anything. The former mansion of the Argenti Family from Genoa, if it was not available as a hotel they could sell tickets just to visit it like the Biltmore House. It is not the only historical mansion in the area that has been converted into a fabulous hotel. Others include the Archontiko Riziko, The Voulamandis House, The Sourediko,The Topakas House and other amazing properties in Kambos which you can find on Booking.com's Kambos page
For those who want to stay in or close to the Mastic Villages I recommend a couple places. For those who don't mind spending a little extra for comfort try the Medieval Castle Suites, a Hotel complex in Mesta that combines all modern facilities with the experience of living in a 14th Century village. If you want something more simple but no less pleasant then Anna Floradi Apartments has studios for two or four people, with kitchenette, air-conditioning, refrigerator, running hot water, private bathroom, satelite TV and central heating fore the winter months. We stayed here and they were fine. To Petrino is a traditional 19th-century building. It features free Wi-Fi and air conditioned rooms with access to the grounds or with views of the medieval village of Vessa. Also in Vessa the Traditional Hotel Ianthe is comprised of 2 historic buildings. The Neocalssiko building was built in 1880 and the Kamarospito was built around 1750.
In Emporio which is close enough to the Mastic Villages to visit, we stayed at the Emporio Bay Hotel which was clean, friendly, a 2 minute walk from the beaches, tavernas and the shops, had a really nice swimming pool and a lot of nice people who came back year after year, always a good sign. This is probably your best bet if you want to stay on or near the sea. Hotel Almiriki is located on Lithi bay, on the southwest of Chios. It features a sun terrace with hot tub, a beachfront café-bar, and rooms with free Wi-Fi and like Emporio Bay is close enough to visit the Mastic Villages.
Karfas is a beach town where most of the islands hotels are located. If big resort hotels are your thing then Golden Sand Hotel is a Catagory A located on the sandy beach of Karfas, 7 km from the center of the town of Chios and 4 km from the airport. Built on 3 acres of waterfront property it has an Olympic sized swimming pool and 108 airconditioned rooms. Aegean Dream Hotel on the beach offers self-catered residences. It features a spa with gym and a swimming pool with free lounge chairs, towels and umbrellas. There are smaller, family run hotels as well like Evagelia Apartments which offers self-catering accommodation with a private balcony overlooking the Aegean Sea. Plaka Studios is a seafront hotel located just 500 ft from Karfas Beach. It offers rooms with kitchen and free Wi-Fi access, some enjoying panoramic views of the Aegean Sea and the sunrise.
You can see these and other hotels on Booking.com's Chios Page with photos, maps, guests reviews and booking information.
I recommend booking hotels and ferries through a reliable Greek travel agency wh can keep things running smoothly, which in Greece often don't. Hahathakis Travel in Lesvos can book hotels on Chios as well as Lesvos and any of the islands in Greece, Athens, trips to Turkey,
ferries, flights and tours.