You can learn something about a philosopher by examining the questions s/he wants to answer. Below are my idées fixes.
E P I S T E M O L O G Y
Truth and epistemic value
Is truth the sole fundamental epistemic value?
Is all derivative epistemic value instrumental epistemic value, or are there pathways of epistemic value derivation that are not instrumental pathways?
Does the view that truth is the sole fundamental epistemic value inevitably lead to some version of the swamping problem?
Can the epistemic value of believing in accordance with the evidence that one possesses be understood as deriving wholly from the epistemic value of truth?
Internalist properties and their significance
Can internalists in epistemology get anything right? If so, which epistemic properties are internalist?
Do internalist properties in epistemology have more than contingent epistemic value? In particular, do they have real rather than merely apparent epistemic value in demon worlds, where instantiating them will guarantee unreliability? If so, can we explain why, or must we add these properties to the list of fundamental epistemic values?
Is the kind of rationality of interest to internalists in epistemology merely a kind of excusability, or does it have a more robust sort of epistemically normative significance?
Reasons, justification, and rationality
Are all justified beliefs necessarily justified by reasons? If one believes for sufficient epistemic reasons, is that sufficient for one's belief to be doxastically justified?
Are normative epistemic reasons the sole fundamental units of epistemic normativity? Or is there another layer of normativity, at least as fundamental, that enables epistemic reasons to do their work?
Are all rational beliefs justified beliefs? Are all justified beliefs rational beliefs?
Is epistemic justification a function of objective epistemic reasons that one possesses?
Evidence, possession, and evidentialism
Are reliabilism and evidentialism best understood as the same kind of theory? Or should they be understood as contributing to two different levels of analysis, like the buck-passing account of value and the hedonist account of value? Can any synthesis of reliabilism and evidentialism succeed?
What is evidence? Does it consist in mental states, facts, propositions, or something else entirely?
What does it take to possess some piece of evidence?
Is the relation of possession that one must bear to a piece of evidence for it to make a difference to one's degree of epistemic justification analyzable in externalist terms? If so, what sort of externalist analysis is best?
V A L U E T H E O R Y A N D P R A C T I C A L R E A S O N
Is the property of being valuable analyzable into more fundamental normative properties/relations, or is it one of the most fundamental normative properties?
How does value derivation work? When X is valuable simply because Y is valuable, is that always to be explained in terms of some instrumental connection between Y and X?
How many distinctions in value do we need, and which are the most important ones? Does the distinction between fundamental and derivative value line up with the distinction between intrinsic and extrinsic value, or with the distinction between final and instrumental value, or with neither?
Perspective and objective normativity
What subjective factors, if any, are capable of making objective normative differences?
Is obligation a function of perspective? If so, how so?
Are there any genuine norms on our actions or attitudes that cannot be excusably violated?
Is excusability itself best understood as consisting in meeting some secondary norm?
Can rationality be indirectly analyzed in terms of appearances and objective reasons—e.g., as responsiveness to apparent objective reasons?
Are the requirements of coherence genuinely normative?
Motivation and PHI-ing for Normative Reasons
What sorts of things are motivating reasons? Are they mental states, facts, propositions, states of affairs, or something else entirely?
Are there several basic motivational relations, or just one?
What does it take to act or form attitudes for normative reasons?