Photoshop CS5, dear ^^.
I only use it because I already had it for years (for other purposes). It’s an okay choice to get a feel for digital drawing, but… It’s old and unstable…. kinda like me lol
Also, I can’t find the Corel Painter installation disc I received, like, 10yrs ago…. I’d love to work with that program, it’s more “painty”. There you have a palette where you can mix colours yourself and all! It’d be more “native” to me, but, well, you work with what you’ve got, right? ^^
Sorry for the mini rant 
test 