Everyone has a favourite, but I like Humbrol for the range of shades, and because they have semigloss as well as flat finishes. I like building a lot of old stuff, and the Humbrol colours seem to be the closest match, and that applies to their gloss finishes as well. They hav ea maroon and a dark blue that are just about bang on for what Ford was using in the '30s and '40s.
That said, I'll use Model Master and Tamiya paint if what they have is closer to what I want.