Edison invented the stock ticker after his failed vote counter - very successfully learning from his mistake of making something unwanted to making something invaluable. His greatest personal invention has to be the phonograph. Absolutely brilliant. But, being practical, he realized that he could hire people and create a research and development organization. The first of its kind and so many things were created from it (General Electric spun out of it) and from the many research labs that followed in the 20th century one can almost say he invented the 20th century.
In part this was due to necessity - the invention of the light bulb is fine but without the hundreds of inventions and enormous capital necessary for the power grid it would not have had much effect.