I used to have the otterbox defender for my iphone 5, but it was so annoyingly bulky I had to get something slimmer. I went with the shocksuit from body glove mobile and couldn't be happier. It provides the same level of protection, but doesn't look like you're carrying around a brick. They also make different models of the shocksuit for basically every different type of phone. The other thing is they're about 30 bucks, but I got it shipped for free and took off another 20% off with the code JP20 on their website.
Mobile Phone Cases by Body Glove Mobile
Best Phone Cases | Screen Protectors, Samsung Cases, & iPhone Cases | DBA Cases | DBA Cases, Inc.
Check out their new Nano Screen Protector Line - better than tempered -