The Queen of Pop took 17% of the 750,000 votes cast in the poll, leaving Aussie superstar Kylie Minogue trailing in second place.
She also beat the Princess of Pop - Britney, who came in at number nine.
British stars who made it into the top 100 were Dido (21), Gabrielle (41) and Sharleen Spiteri (49).
The Spice Girls as a whole were at 44, with Mel C in at 58, four places above Geri (62). Emma Bunton, Mel B and Victoria Beckham were nowhere to be seen.
Denise Van Outen will count down the Top 100 on VH1 from 30 September to 4 October.