Yes, yes, yes Rachelle Farrell and Will Downing is also my very favorite, as is any duet with Donny Hathaway.
Born Again: Billy Preston and Syretta too!
How Do You Keep the Music Playing: Patti Austin and James Ingram
When I Fall In Love: Harry Connick Jr. and Celine Dion
You Don't Bring Me Flowers: Barbara Striesand and Neil Diamond
California Love: Dre, Tupac
I.O.U Me and I'm Lost Without You (BeBe and Cee Cee)
Love Saw It: Karen White and Babyface