The Aesthetic-Usability Effect is a theory that people perceive more aesthetic designs to work better then less aesthetic designs. Below are three examples from my life that I would consider to achieve the effect.
Example 1: Dyson Vacuum
A very popular example of the effect at work. Dyson is a brand well known for its quality above and beyond other vacuum cleaners. While a considerable amount of this certainly comes from the actual effectiveness of the product, it almost certainly out performs brands of similar quality because of the brands well known unique look. Unlike many companies behind such common household products, one can tell Dyson have put a lot of thought into the functionally useless design of their product, and they have since the beginning. It has certainly proven to be effective.
Example 2: Toaster
This is a more personal example than the last. Toasters do not vary greatly in their quality. A task as simple as toasting bread in a satisfactory way for most on even the cheapest product. However this sleek and retro design would most definitely make it stand out against other brands, even if its function is the same. A much more positive relationship can be made with such a sleek model than the boring old silver toaster. The knobs, buttons and dials make even this almost always automatic product seem easier to use than the competition.
Example 3: Dragon Egg Paper Weight
A very simple example. Function wise there is literally no difference between this and a bland one. I can confirm aesthetics was the sole reason for my purchase of this item. The well designed item, I thought would do a better job at the effortlessly simple task of holding down papers, regardless of its higher price tag. It again comes down to forming a relationship, even to an item like this. Extremely simple items such as this are perfect in demonstrating the effect as their function is so similar that bias for aesthetics can easily be observed.