Samples are often distributed with SDKs to provide real world details on how to use the product. Some samples are complete applications, some are bare bones console applications and some are just plain text tutorials with code snippets.
How do you like SDK samples to be presented?
All of the examples you provided can be helpful to different people and/or at different times.
Personally, I like to see a lot of deep textual treatment of the relevant subjects and lots of small, focused code snippets demonstrating salient aspects of the SDK.
A 'toy' application used to demonstrate both the breadth and the depth of the SDK can be very useful as well.