PhotoShop. After all it is the standard program of the industry (also the one I used at school)
Corel Draw is very efficient too but I have not used it in a while.
I dont know about writing text with a graphic program, but if you reffer to coding, it is only implemented on advance skinning or adding features to a skin if the skinning program doesnt have them, on either case you dont need a graphic program for that. You can easily do it on notepad.