Without having counted the exact amount of animation footage he did, I would say that George Germanetti was the most prolific of all the Popeye animators. His work spanned three different time periods of the character - Fleischer, Famous Studio, and King Features.
The first Popeye credit for Germanetti was on the 1935 Fleischer cartoon 'Choose Yer Weppins'. He animated primarily for Willard Bowsky's unit until 1939. At that point Germanetti's work wasn't exclusive to any particular unit until the later Famous Studio years when he became part of Al Eugster's crew.
Germanetti had an aesthetically appealing look to his Popeye (contributing to the overall appeal of the Bowsky unit cartoons) and his style must have been well regarded during the Fleischer and Famous Studio eras as evidenced by the use of his drawings for publicity art and posters. I have posted some examples below of Germanetti's scenes and artwork.
To see a photo of George Germanetti (and other Famous Studio animators) check out Mark Mayerson's amazing site on animator Al Eugster at:
Choose Yer Weppins - 1935
I Ski Love Ski You Ski - 1936
Hold The Wire - 1936
Popeye Meets Ali Baba's Forty Theives - 1937
A Date to Skate - 1938
Hello - How Am I? - 1939
Olive's Sweepstake Ticket - 1941
Me Musical Nephews - 1942
Happy Birthdaze - 1943
The Island Fling - 1946
Wotta Knight - 1947
Alpine For You - 1951
Popeye's 20th Anniversary - 1954
Parlez Vous Woo - 1956
Popeye's Double Trouble - 1961
Fleischer Studio in-house publication cover (thanks to Jerry Beck)
1940's generic 1 sheet poster
1950's generic 1 sheet poster
Next Animator ID: Frank Endres