In general, rubber / silicone cases are more durable than plastic ones. What i am currently using are two silicone iphone 4 protectors from sourcingmap. The highlight of their iphone 4 cases come with free front screen protectors. I have also heard good sides about brand cases: Belkin Armband ($29.99), Mivizu Silicone Case ($16.95) or the Beetle Case by AGF ($34.99) while the two cases i have are priced at $ 3.49. They provide pretty good protection and fit my phone perfectly, i can get access to all the features with no need to remove the case. Highly recommended.