I am a big fan of personalized products like NikeID (including both my running sneakers and golf shoes) and their corresponding web / application experiences. The latest Google Android device - the Moto X - combines hardware and software customization in a way that only Google can do. It's very well done. The Moto X can be purchased online at Google's Play store (Moto Maker). There, users customize three aspects of the phone: styling (color, shell, etc), features and accessories. The hardware customizations are relatively obvious - but also fun in a way that is similar to shopping on NikeID.
The unique part: users can attach their Google ID by authenticating their Google login. This then enables users to customize the software (ie backgrounds and welcome messages). It also enables Google to deliver an authenticated phone already connected with a user's synced apps, contacts, etc. In effect: once the user inputs his / her password, it's a fully custom phone from appearance to application / content.