Depends what sort of level you are doing changes, I tend to use faststone (free) for basic editing.
I occasionally use photoshop but never got round to using it properly, I use it on a needs-must basis.
Used to use gimp at one time, never made friends with it either.
In a time of universal deceit - telling the truth is a revolutionary act. George Orwell
When the debate is lost, slander becomes the tool of the loser. Socrates