That is a difficult question as it depends on the individual. Everyone will have a different opinion on what they find most memorable. Some of the more memorable logos out there are those belonging to popular corporate brands such as Apple, Nike and McDonald's. In fact, some studies have found that these logos are so well designed and distinct, they can be recognised with just the outline.
However, there are some other logos that are also renowned for their memorability - the Coca-Cola, Pepsi and VW logos come to mind. Even the BP logo has become highly recognisable.
In terms of professionally designed logos, there are a number of custom logo companies that create interesting designs for their clients. From the creative typographical logos for bands to the more subtle geometric patterns for businesses, there are a lot of potential memorable logos out there.
Ultimately, everyone can decide what logo they find the most memorable. It could be the logo of a business or organisation that they support, the logo of a memory-stirring event or something completely different. To answer the question of 'what is the most memorable logo' we have to leave it up to the individual.
