I and my partner recently went to the Island of Kos on a cheap, late deal package with Thomson. We were sent to the Cosmopolitan Hotel just outside Kos Town.

The hotel was brilliant. The staff all spoke really good english and were helpful and friendly. The room was spacious, with a personal bathroom (wc, shwr/bath) use of a TV if wanted (at a small cost) and the beds comfortable.
It is not designed as a family hotel, but there are family hotels nearby.
There was a GORGEOUS swimming pool, decent sized on a personal terrace, with lovely sunbeds and a brilliant poolside bar/cafe.

The breakfast was traditional Greek; friuts, sweetbreads, ham and cheese, friut juice and coffee/tea to finish; and we weren't hurried. We often sat on the outside terrace munching contentedly on the delicious ham.

Kos Town was only about 30 mins walk away, or you could take the bus for about 40p (you can do the length of the island by bus for about £1.60!).

As we were on B&B, we were worried about finding food in the evening. No worries there! There are plenty of restaurants along the main road that goes into Kos Town, al reasonlably priced, and with all the variety you could want.

All the facilities are nearby, including about 4 'supermarkets' were you can get yesterday's paper and bottles of water, and plenty of souvenir shops.

All-in-all, a great location. Lovely rooms, great pool, friendly staff, and all the facilties nearby that you could need.

If you are planning to stay in Kos, then I would heartily recommend this hotel.