I'm slowly starting to switch to Pferd machinist's files. I'm attaching some useful info from them so you know what you're looking at. One Pferd file that I want is the Flat File Plus - one safe edge, chip breakers, etc.
https://www.pferdusa.com/products/201a/201a02/201a0202P.html
One of the first files I suggest you get is a lathe file. I think the first of Ken's links above is a lathe file. The one I have is this one:
https://www.amazon.com/Nicholson-American-Pattern-Single-Rectangular/dp/B006P2XGDU. I have the 8 and 10" and they work so well that I may buy more from Pferd.
You need at least one single cut/bastard file for roughing, the length of which depends on your anatomy. For me, at 5'-8", I prefer a 10" file.
You need at least one double cut file for finishing. I prefer an 8" for this.
You need at least one round file for enlarging/moving holes. I have several but surprisingly, I prefer a chainsaw file with a constant diameter most of the time.
For fine work, I use Grobet files. These are like riffler files for metal. It is amazing how fast and precisely these cut.
I must have 25 or more files scattered around in my shop but the lathe file, bastard and smooth files are the work horses. I particularly like them for drawfiling.
Brands that I know to be good: Pferd, Grobet.
Brands that work pretty good: Nicholson, Simmons.
I'm sure others will be along shortly.