Apples Notes because nothing else has the perfect amount of formatting, alongside exceptional sync.
Also Apple Mail for the same simplicity reason - Geary on Gnome is close-ish, but goes too far down the simple route. How does it not have a refresh button??
Also Logic Pro, mainly because there aren’t any fully FOSS alternatives that even attempt a full-featured DAW, let alone with Drummer etc.
I also ‘prefer’ Apple’s productivity suite over everything else, because it has by far the best UX, but I’m totally fine with LibreOffice too.