It all depends on which razor I'd be choosing for the rest of my life, because for me, different blades wrk best in different razors.
But for the sake of this discussion ..... Feather !
Gillette spoilers, one of the best blades ever! Paired with my birth year razor a Gillette 1958 d3 tv special, they make for a great shave every time. I've got over 1650 of them, enough to last me, at one per week, nearly thirty two years. I hope I can live long enough to enjoy them all. After that I'll grow a beard