Here is a list and photos of the tallest Ferris wheels in the world. The original Ferris wheel was designed by George Washington Gale Ferris, Jr., as a landmark for the 1893 World's Columbian Exposition in Chicago. The term Ferris wheel later came to be used generically for all such rides.
“These wheels have almost replaced the skyscraper as icons,” says Dennis Speigel, president of the consulting firm International Theme Park Services. You’d expect him to say that, since his company is busy building tall, very tall Ferris wheels.