Dennett, to me, is the most relentlessly naturalistic of the modern philosophers, and as such his work is essential to understanding how it might be possible to have a scientific account of the mind going forward. The latest incarnation of his approach is the "Fantasy Echo" theory of consciousness. Dennett's "Sweet Dreams" is a collection of essays relevant to his functionalist content-first account of consciousness. It is imperfectly edited, but would be my first choice for a general overview of his approach, and introduces the Fantasy Echo theory. I would also recommend several of the critical volumes on Dennett, because he tends to respond unusually well to critiques, and his views have been clarified more for me by his response to the critiques than to Dennett's own essays.

Kim Sterelny, who has written critiques of various aspects of Dennett's work, is a nice complement to Dennett because he agrees on Dennett's general physicalist approach but differs on some interesting details regarding the "intentional stance" and the representational view of the mind. Sterelny's "The Representational Theory of Mind" is dated, but to my mind is still a classic introduction to the fundamental issues involved in a physicalist theory of mind. I still refer back to it after years on the shelf when I want to get a better understanding of what motivates various physical models for the human mind.

Another good souce is the critical literature on Paul and Patricia Churchland, who like Dan Dennett are very good at responding with clarity to their loyal opposition. THe Churchlands are basically neural eliminativists, they look for models that reduce folk psychology to something neurological. Dennett, in comparison, seems to take a slightly more realist view of intentional psychology, and I find his case persuasive.

Millikan goes pretty deeply into the reference problem and has an interesting and plausible approach based on the skills for re-identifying things from one context to the next. It is useful for realist philosophy of science, an epistemological approach to concepts, but I think scientific realism is pretty much a given if you are following people like Dennett with interest.

If you are looking for philosophy of science, my two favorite modern sources are Susan Haack ("Defending Science: Within Reason") and Ian Hacking's idiosyncratic but wonderful text, "Representing and Intervening."

kind regards,

Todd