Clare:
Frankly none that I've read to date really jump out as "outstanding" to me. Given that everyone is different from the perspectives of experience, skills, artistic / creative abilities, etc., what's inspiring to one person is, "So what?" to another.
Personally I'm not a "production" artist whose livelihood depends on my abilty to generate time and again super-creative collages that blend textures and type effects and images and special effects into a surreal final result. (not that you are, either) This type of person needs way different inspiration than I do.
The books I mentioned "aren't bad," especially if you get them 2nd hand for less than full retail price. Not a lot of specific detail on the "how" (techniques) -- these are not 'step-by-step' how-to books, but each has lots of images for visual inspiration plus artists' commentary on thought processes, creative decisions, etc.
Another that might be worth a look was co-written by Deke McClleland and Katrin Eismann.
Photoshop Studio Secrets
Amazon.com link
This is another with each chapter dedicated to a different artist. Interview, Q-A, images from concept to final result.
Again, I'd suggest browsing at the local bookstore, then decide if you want to part with your hard earned money.
Then buy it used!
Hope this helps...
~Danny~