Philosophy, it has been said, is a series of footnotes to Plato. While this is surely an exaggeration, it is good for philosophers to say as carefully as they can how they agree and how they disagree with Plato.
First, I will mention two of my major agreements with the master: 1) the primary task of philosophy is to get clear definitions of our most central concepts, and 2) the concept of the Good is not identical with pleasure. Right or virtuous actions aim at the Good, and the Good is inclusive of more particular goods, such as Truth, Beauty, Justice and Freedom. It is not mere "happiness."
I disagree with Plato insofar as he believed that our central concepts were fixed realities independent of our minds. Throughout the centuries most philosophers have dissented from Plato's belief that the concepts are Platonic Forms; but they have nevertheless taken them to be fixed targets for analysis. That is to say, they have assumed that Freedom, Time, Space, God, Justice, Cause, Person, etc. do not change throughout human history and that it makes sense to search for the eternally correct definitions of these concepts.
I go farther than this in distancing myself from Plato. Not only are these concepts not Platonic Forms, concepts can, do, and should change. They are not fixed targets to be the subject of analysis. Instead, when philosophers craft clear definitions of these concepts we ought to understand what we are doing as proposing improved versions of old ideas, which will enable us to think new and more productive thoughts.
Philosophy, as I conceive it, ought to be seen as a creative endeavor with more similarity to art than to science.