NFL: I play draftkings, fanduel, yahoo, fantasydraft, and fantasyaces
NBA: Draftkings, fanduel, yahoo, fantasydraft
PGA: draftkings, fantasydraft
Both DK and FD have advantages over the other. For instance FD shows how each individual lineup is doing on the website, while DK does a poor job of this. FD makes it easy to cancel contests and it is a nightmare on DK. On the other hand, editing and splitting lineups on DK is easy but a burden on FD.
I would suggest playing FD as well. And if you greatly prefer one choose that