We had a really wonderful time staying in Castellammare, at Vincenzo's lovely apartment. The photos don't do the terrace justice - what a view! It was a wonderful place to sit and eat breakfast in the morning, to sunbathe during the day, and to soak up the atmosphere in the evening. There are a great range of restaurants and cafes on the doorstep, and lovely little streets to walk around in the town. Definitely hire a car if you are planning on staying for more than a week - you'll want to get out of town and explore the beaches at Scopello/San Vito, and check out Erice too. Also, the local Pane Cunzato are absolutely delicious as a lunchtime treat.
The apartment was clean and tidy - basic, but it's all you need when the weather is glorious and you just want to be outside. Perfect location, and only 25mins from Palermo airport. Would highly recommend to anyone thinking of going to Sicily!