The first home was David Ross, 42, from Sutton, dressed as Fred Flintstone and brandishing an inflatable club.
His time of three hours, seven minutes and 34 seconds earned him the title of fastest cartoon character.
The City sales account manager, who was running his 175th marathon, said: "I got a bit tired saying 'Yabba Dabba Doo'.
"But it's a very proud moment. It's been a good day."
Meanwhile, Princess Beatrice became the first member of the royal family to run the marathon. The Princess, 21, crossed the finish line in five hours, 15 minutes and 57 seconds as part of a 34-man "human caterpillar" which set the Guinness World Record for the most number of runners tied together.
Police officer Jill Christie, 27, from Brentford, north-west London, was dressed as Superwoman and was raising money for Crimestoppers.
She became the fastest female dressed as a super hero, finishing in three hours, eight minutes and 55 seconds.
London Marathon runners world record 2010 video