Hunter/Garcia
Lennon/McCartney
And Nilsson of course
Oh yeah, Billy Joel, Richard Thompson, Sting, Stevie Wonder,Jagger/Richard, Chuck Berry
The one who never seems to get mentioned in these SD surveys and has been by far the biggest in the last 20 years Diane Warren,(male or female) look her up and be surprised, 5 Oscar and Golden globe nominations, 75 top ten hits in the last couple of decades.
Its the sheer range of artists she writes for that is possibly the most surprising.
Carole Bayer-Sager has written plenty of stuff too.
As for influencial, how about David Foster, better known as a producer but he has written quite a lot of stuff, lord alone knows how many awards he has.
Another sonwriting team that never gets mentioned, the brothers Gibb, better known as the Beegees, they’ve been at it for around thirty years, that whole disco thing would have been so differant without them, they’ve sold around 100 million copies of their own material, add to that total all the other artists who recorded their stuff and I’d guess they must be around the top five of all time.