I don't think that there is a single useful non-overlapping set of branches. For instance, philosophy of mathematics and philosophy of logic are, on some views, contained within one another (on some views philosophy of logic is a branch of philosophy of mathematics, on others the containment goes the other way). Both take up issues that are also clearly within Epistemology and Metaphysics.
The way I would characterize the branches at the top level is:
- Value Theory (includes moral and political philosophy and the philosophy of art)
- Philosophy of Language
- Philosophy of Mind
- Philosophy of the special sciences (philosophy of mathematics, philosophy of physics, philosophy of history, etc.)
This list has a good deal of overlap, too. Metaethics arguably straddles all of the first 3; philosophy of mind overlaps with at least metaphysics, etc.
Philosophy of language seems an odd man out, but given its importance in analytic philosophy and that it cannot be comfortably subsumed under any other branch on my list, I'm stuck with the oddity.