What’s good? Big ipad with apple pen or something? What do people use these days?
On PC I use and love Clip Studio Paint. It’s decently priced for what you get and often on sale (tho admittedly they’ve changed the pricing system recently which is a bit whacky, so I still use my old Version 1). However, many people use Krita nowadays, it’s extremely good software, open source and completely free! On iPad I think the way to go is Procreate for rasterised images, and Affinity Designer is pretty good for vector art stuff