I use a combination of Apple Barrel, Model Masters Acryl, Tamiya Sprays, and Tamiya brush on.
For Primer I exclusively use Rustoleum brand. I used to use Krylon but they’ve since changed their formula and it no longer dries on PVC plastics (what you usually find on limbs and heads)
For sealers, I start with a base of Testors Dull Cote spray, then use brush on Testors Gloss Acryl for any other details that need to be gloss. Of course if the figure is glossy all over, I’ll just use a Testors Gloss Cote spray.