This question is calling my name.... And it's really hard to narrow it down, but if I'm going to choose someone famous, I might go for Barry Gibb. Or Adele. Or Dolly Parton. Or Paul Simon. Or Carole King. Or Carly Simon. Or Laura Nyro. Or Lady Gaga. Or Debby Harry. Or Enya. Or Paul McCartney.
Wait! Just one??? <<sigh>> Keeping in mind, collaborating with me will just be a nuisance for any one of them. Maybe....Paul Simon. No, no, no, make that Adele. No...better go with Barry Gibb.
Actually, I really like collaborating with people like PaulAds, Skub, Neil C....who did I forget???