Korg

The history of Korg as a musical instrument manufacturer is on a global scale.  Briefly, Korg was founded in 1962 in Japan.  Korg is best known for making electronic musical instruments - specifically keyboards and electronic organs - as well as audio processors, guitar pedals, recording instruments, electronic tuners, guitar amplifiers, and electric guitars.

(The full history of Korg can be found on Wikipedia.)

The full list of Korg products as found in the United States can be found the company's website.

My best recommendation for Korg products is at the professional level.  I am suggesting this market because Nick Rhodes of Duran Duran once used Korg for his recording needs.  

Consider the company's website to determine your level of proficiency and worth of purchase.

My take away -
In the Play It Sunday post featuring the Korg EK-50 Entertainer Keyboard, learning is best meant for beginners who are familiar with the keyboards as an instrument and are now learning more advanced aspects.  With this said, the Korg EK-50 Entertainer Keyboard pales in comparison into what Korg is truly known for...and is best meant for professional proficiency.

Explore the Korg website for more details.