CES had a ton of case vendors, so it would be pretty easy to find one that suits your personality, but if you want a truly unique case, you have to make it yourself. Fortunately, last year I met the folks at Jaymo (http://www.jaymo.co) and I picked up their PixCase for the iPhone 4. The best testimonial I can give is that my wife uses it as her everyday case!
Jaymo specializes in personalized gift products, including pens, mugs, keychains and, of course, iPhone cases. All of their products have a place for your own photo, so you can use their templates to print a photo, logo, or personalized insert and create an original.
New this year are their PixCase cases for the original iPad and iPad 2, and the ability to create monogrammed and personalized inserts leveraging their fashionable PIY (Personalize It Yourself) designs.
The nice thing about these cases is that you can change the photo on a whim, as your family grows, as your kids grow up, or when you get a new boyfriend -- whenever! And since so many iOS devices get handed down to other family members, they can keep the case and replace the photo insert.