On full frame it's always been 17-40, 35mm and 85mm... I know, 17-40mm is not a prime, but if Canon had a 20-ish mm f/2.8 prime with the build quality of the 17-40 for a similar price I'd have that instead.
On Fuji I think the 14mm, 23mm and 56mm would be my kit, although I rarely shoot long, so perhaps 14mm, 23mm and 35mm would be a better choice.
Eitherway, I now have the 18mm and the 35mm on an X-T1, the 23mm and a new body will follow, but perhaps I'll hold off on the 56mm.