My lifetime estimates for Switch is 90-95M at this moment (due to nintendo replacing their consoles fairly quickly), so PS4 by default.
I wont be surprised if the Switch does manage to crush the 100 million mark, though.
Bet with Intrinsic:
The Switch will outsell 3DS (based on VGchartz numbers), according to me, while Intrinsic thinks the opposite will hold true. One month avatar control for the loser's avatar.