I love reading beer books.
It goes without saying that Palmer's How to Brew is great.
The Designing Great Beers book is good and has lots of information but is somewhat strange in the whole thing is based on a handful of entries in a US competition.
The books on different beer styles are normally interesting, I find, but are somewhat hit and miss. Often they're more inspirational than informative.
The "brewers elements" books (Yeast/Malt/Hops/Water) I have enjoyed reading.
Yeast is probably the best, both in terms of information and practical knowledge. I have re-read this book multiple times, but to be honest requires a PhD in Biochemistry (which I don't have) to fully understand. I aspire to setting up my own yeast lab as described in the book but let's get serious it's highly unlikely.
Malt was interesting but I didn't get too much practical information from it.
Water is also at the same technical level of yeast (chemistry-wise), with massive amounts of information. To be honest I feel the water chemistry section in Palmer's How to Brew book is more usable for all but the 0.001% of us. I do object to the paraphrased "Declaration of Independence" in the Water book. You would have thought beer is a US invention. Other than that, good book.
Hops, I am currently reading so can't yet comment on.
I have made more than a few of the recipes out of Clonebrews and this book has provided a lot of inspiration as well.
Read on.
[Is the Experimental Homebrewing book the one with the Cock Ale, i.e. the one with the boiled chicken in it, or am I thinking of something else?]