After I read the 6 original Dune novels, I'm thinking of starting on Asimov's "Foundation" series. In what order should I read them - chronologically, or in order of their publishing?

Excellent series, I am sure you will enjoy it.

I would suggest reading them by order of their publishing date.

Foundation is one of my favorite series. I would start with the first book in publishing order "Foundation", then "Foundation and Empire" "Second Foundation" "Foundations Edge" and "Foundation and Earth". Worry about the prequel books after you've finished these, as the references in these books won't be obscure. Also consider the robot novels at some point if you really want to flesh out Asimov's universe (they play a role in the later Foundation books), and also a stand alone novel "The End of Eternity" as this has a tangential bearing on these stories.

Good luck, you're in for an excellent ride!

What a coincidence that you should ask this since I'm currently reading the Foundation Trilogy which consists of Foundation, Foundation and Empire and Second Foundation.

It's an excellent sci-fi series of books by a master author.

Definitely in order of publishing.

If you go for the short route, start with the three original Foundation novels. If you want the touristic route and have enough time available, start with the first two Elijah Baley stories (The caves of Steel and The Naked Sun), then a few robot stories (I, Robot and/or Robot Dreams). Or, the other way around. Then, the later Baley-stories (The robots of Dawn and Robots and Empire). Then, Foundation, Foundation and Empire and Second Foundation. Finally, the last four Foundation novels: Foundation's Edge, Foundation and Earth, Prelude to Foundation and Forward the Foundation. Forget about the Extended Foundation novels, written by other people. Even though they're good books in their own right, they turn the Asimov heritage into an action fest that (gasp!) even could be used for a film script. Asimov isn't about action, it's about brains, and how violence is the last refuge of the incompetent.

Hehe, I like how you snuck in that little quote from Foundation.

Yeah, and I don't even completely agree with it... too often it seems violence is the FIRST refuge of the incompetent.

Personally I dislike the latter Foundation novels, after the first three.

The robots books I seem to recall as being good, but haven't read them for like 15 years, maybe I should.

I'm on "Second Foundation" now (as part of a combined trilogy book). I'm already starting to get a little sad that I'll be finished soon. Do the follow-up Foundation books by Asimov live up to the first three? Legend mentioned them but I'd like a little more feedback. Thanks.

Yes definately! Their plotlines are not like the fist three novels; that is, they are not a sweeping epic timeline of the Foundation's history. More of a discover and adventure novel focusing on a main protagonist and his problem concerning the Second Foundation (trying not to give anything away here). If your expecting an exact continuation of the 1000 year history of the Foundation and a rise of the Second Galactic Empire, well, you'll be disappointed. The end of the third book of the original Foundation trilogy is a good place to stop, and read the robot novels (at least "Robots and Empire" if not all of them) then continue with Foundation's Edge and Foundation and Earth. If you really want to be blown away by how BIG Asimov's history is, read also "The End of Eternity" by same, for a large payoff is at the end of Foundation and Earth regarding that novel.

Hope this helps!