Epoxy paint sticks well to any prepped surface, but tends to chalk eventually. Polyurethane paints need careful prep, but the shine lasts. Awlgrip and other catalyzed polyurethanes require a lot of skill to apply, one-part topside paints such as Easypoxy or Brightside are very easy to apply.
I used to put premium paint (Imron) on aircraft, because they are not subject to wear: you want the best sun resistance. On a boat, the decks and cabin sides (even hull, if you are me) get banged up with dinghys, the wrong shoes, and me lumbering around, so I use something I can fix with my poor skills. I use a high-build sandable epoxy primer over original paint (sanded) or over metal etch and zinc chromate, and then roll Easypoxy over the sanded epoxy primer. This is easiest: the epoxy primer sticks to anything, and the sandable means that it is easy to prep. Unlike classier coatings, Easypoxy rolls right on in three thin coats and looks pretty good for an amateur like me.
Some guys on this forum do gorgeous paint work. Some of the boats are just wonderful looking. I have neither skill nor time to do that, if you need advice on that kind of a job, go elsewhere :-)
1975 32' Flybridge Sedan, twin Perkins 6-354 diesels, 1:1.53 velvetdrives, 16 X 19 props. Merritt Island, Florida