Silk (legend) layers if you want them, front & back
(EDIT: also Edge.Cuts for the board outline is mandatory)
Drill file or files in the format they accept.
“Drill map” is usually not needed, sometimes they even explicitly tell they don’t want it. Drill files are usually in Excellon format. More often than not plated and non-plated holes should be in different drill files (PTH and NPTH).
But this can’t be emphasized too much: always read the manufacturer’s instructions or ask them.
I always give them the full set of 9 even if some layers are not used on the “don’t ask for trouble” principle. It makes very little difference to the zip size even less so if it’s empty. Actually I always find a use for B_SilkS because I mount some components on the back.