If you are looking for a solid case and the unusual shapes for your iPhone 4, the latest product from Element Case is certainly one of the major candidates. It's called Vapor COMP homes and is a great attention to detail, very durable, made from the finest materials and with pinpoint accuracy on the shapes of the smartphone and its ports.
The supporting structure of the case is aluminum, a material which combines strength and lightness, perfect for this kind of products. The buttons (volume and power) are made of polycarbonate, as the side bands which are very useful to have a good grip. All ports are accessible from the aisles to the dock to sync, even the camera is not covered but without compromising on the protection of smartphones.
The back of the case is covered by a layer of a special material called "Ultrasuede", a kind of piece soft very pleasant to the touch. This part is black, while the aluminum body, in addition to silver color base, you can select it in five colors: Black, Blue, Pink, Red and Orange.
You can find it on elementcase.com