Microwave Oven Combo

Using a wall oven with microwave can create a more ergonomic cooking experience.  I like them because they free up the space below the range for storage of cooking ware and accessories and I like the height that the built in gives you. 
In a single wall kitchen I would have this full height casework on one side of a counter and a built in refrigerator at the other side to balance out the design.

Contemporary Kitchen design by Calgary Design-build Fifth Element Homes

I think this combo unit that includes a small refrigerator and a coffee maker is a create space saver for a small kitchen that still wants all of the gadgets built in:

Asian Kitchen design by Toronto Interior Designer XTC Design Incorporated