Much of the work of compiling and maintaining lists of papers and other philosophical publications available on the Web has already been carried out by others. In particular, David Chalmers' Web site includes comprehensive references to philosophical papers published on the Web, as well as a guide to the philosophy of mind and, as one would expect, his own publications on consciousness, modality and two-dimensional semantics.
For those who desire an introduction to a specific topic in philosophy, the Stanford Encyclopedia of Philosophy offers an impressive, and growing, collection of articles.
It need hardly be said that the following are personal recommendations. My aim here is not to list books that would commonly be known to undergraduate students, but to suggest titles that might otherwise escape notice. This list is far from comprehensive, but not altogether random either.
My induction into the philosophy of language came as a postgraduate student, although as my undergraduate Honours thesis reveals, I was already deeply concerned with questions of meaning and truth. I took the historical path into the subject by reading Wittgenstein's Tractatus and works by the logical positivists of the Vienna Circle. A particularly insightful overview of the historical developments that culminated in the Vienna of the 1930's can be found in J. Alberto Coffa, The Semantic Tradition from Kant to Carnap: To the Vienna Station, which is best read after you have studied The Critique of Pure Reason and desire a historical overview of the path from Kant's transcendental idealism to modern forms of "logical empiricism".
Another book in the philosophy of language which has significantly influenced my outlook is Michael Dummett, Frege, Philosophy of Language, 2nd ed. As an aside, if you decide to work your way through this book, a highly worthwhile undertaking, I recommend that you also read the preface. It should be noted that Dummett's coverage extends well beyond Frege himself to include commentary on Russell, Wittgenstein, Quine, Kripke and other exponents of the tradition that Frege's work spawned.
Beyond the philosophy of language itself, there are many books I could suggest. For the moment, a few notable anthologies may suffice.
In the philosophy of mind, my favourite collection of papers remains William G. Lycan (ed), Mind and Cognition, a Reader. The papers reproduced in this volume are not only carefully selected and arranged, but they are also accompanied by well informed introductory comments from the editor. This is a superb example of how to construct an anthology.
Another outstanding collection of papers (which I still have to finish reading) is Darwall, Gibbard and Railton (eds), Moral Discourse and Practice: Some Philosophical Approaches, a superb overview of contemporary metaethics. If you are interested in, or curious about, the underlying nature of moral evaluation or questions of realism and anti-realism as they pertain to ethics, then this is an excellent starting point.
If, as I am, you are interested in and concerned about the question of social equality (and inequality), then Amartya Sen, Inequality Reexamined is the book to read for a thorough and insightful analysis.
For those with an interest in the philosophy of Jacques Derrida, one of the best critical analyses of his early work is to be found in J. Claude Evans, Strategies of Deconstruction: Derrida and the Myth of the Voice.
A book that every law student with a serious interest in the subject should read: H.L.A. Hart, The Concept of Law. Whatever else you decide to read in legal philosophy, if anything, this book is essential. Hart's theory has influenced much subsequent work in the discipline and is a joy to read in its own right as a beautifully clear and well argued theory of what it is for a society to possess a legal system, and the nature of the law as an institution.
If you are interested in contemporary theories of legal interpretation, after reading Dworkin for example, the papers in Andrei Marmor (ed), Law and Interpretation, should deepen your understanding of the issues. Some background in the philosophy of language may be helpful; as I remember, Kripke and Wittgenstein (and not just the former's controversial "interpretation" of the latter) are discussed in several of the papers.