The first neon advertising sign was used for a Parisian barber in 1912. Since then, neon has been used to add color highlights to porcelain signs and advertising clocks, and to create highly ornate and even 'animated' neon signs for a wide variety of brands and retail establishments.
Some of the most collectible neon signs were custom-made or produced in small quantities in the 1940s and 50s for restaurants, shops, clubs, bars, hotels, burger joints, ice cream parlors, auto dealerships, gas stations, you name it. Then there are the more recent mass-produced neon signs, both outdoor and indoor, often representing beverage companies like Budweiser, Coca Cola, Pepsi, and other beer and soda brands.
As with all signs, condition is key, but especially with neon, since replacing it can be an expensive custom job, don't forget to find out if the neon still works!