What is the best painter/styler tool?


I was wondering what the best painting/styling/digital art program is out there? I have photoshop and illustrator CS3, and my goal is to work with large graphic files, poster size, and create my own cool designs and styles. I find the default brushes in photoshop and effects are ok, but i would like to be able to do more. I don't have a wacom tablet yet, but I intend on getting one. Currently I don't feel like hand drawing everything then scanning it. Takes too much time especially if i make mistakes..

I have checked out Corel Painter X, it looks pretty sweet, and is for mac as well. What do others use? or recommend?

Thanks everyone