She may have only just wrapped the last episode of her truly landmark chat show but already Oprah Winfrey’s fame is beginning to diminish. That looks to be the message after the global media powerhouse was knocked off the top spot of Forbes magazine’s annual celebrity 100 list by Lady Gaga.

 

The 2011 edition of the influential poll sees the pop icon’s incredible rise continue with unstoppable momentum at the expense of a woman who has defined the world of TV pretty much like no-one else in a era spanning three decades.

 

Winfrey, chart-topper four times in the last six years, drops to number two, despite bringing in considerably more income than her main rival. She earned $290 million (£180 million) in the last 12 months, while Gaga raked in $90 million (£55 million).

 

But the singer’s creative, non-stop manipulation of her image and career has proved an irresistible combination. “Lady Gaga beat Oprah this year because of her social media power. She's the best example of how celebrities will need to manage their careers in the coming years,” said Forbes editor Dorothy Pomerantz.

 

With 32 million Facebook fans and 10 million Twitter followers, it’s clear that the flamboyant star, whose real name is Stefani Germanotta, is going to take some beating in future. It’s unlikely to be Madonna that provides such a threat, with Justin Bieber, U2 and Sir Elton John her closest musical challengers in the top five.

 

At number nine is Simon Cowell, whose international, trans-media portfolio suggests his profile continues to rise, particularly with the imminent launch of ‘The X Factor’ in America and his new game show, ‘Red Or Black’, which is to be presented by Ant & Dec.

 

But for Winfrey, Forbes’ latest rundown confirms that her remarkable empire is beginning to crumble. She was in Chicago this week, shooting the last two editions of her chat show, which first aired on September 8, 1986.

 

As to be expected, a star-studded collection of showbiz figures were on-hand to say goodbye. A crowd of 13,000 turned up at the United Center on Tuesday night for ‘Surprise Oprah! A Farewell Spectacular’.

 

Amongst the audience were Tom Cruise, Will Smith, Tom Hanks, Beyoncé, Halle Berry and Aretha Franklin. Speaking about the 57-year-old chat show legend, Madonna said: “It's no secret that millions of people are inspired by Oprah. I am one of those people.”

 

So what’s next? Her latest TV venture, OWN (Oprah Winfrey Network), has not enjoyed a particularly successful launch. After going live in January, when it attracted an average of 505,000 viewers, that figure then dropped to 135,000. Oprah admits it is “not where [she wants]it to be” and a major overhaul is underway.

Deserved, she really is the most powerful celebrity at the moment. However I have a feeling Justin Bieber might take her place next year or Adele :P