I've been wanting to do this post for ages, I am addicted to crochet books and am especially prone to collecting vintage crochet books. It's well worth stalking Ebay for good ones or your local charity shop, village fete or car-boot sale.
I love crochet books. Seriously, I love ALL crochet books so it was hard to just choose a few to highlight but these are the ones I use the most and/or have made something or some things from.
Cute and Easy Crochet by Nicki Trench: http://amzn.to/28IAKs4
Geek Chic Crochet by Nicki Trench: http://amzn.to/28IASb8
Learn to Crochet, Love to Crochet by Anna Wilkinson: http://amzn.to/28IAWaS
Crochet Home by Emma Lamb: http://amzn.to/28IAYiU
Handbook of Crochet Stitches by Betty Barnden: http://amzn.to/28IA2PS
Vintage Books - try Ebay or Etsy to find copies of these ones (also someone told me about AbeBooks today, brilliant online vintage book seller)
A Complete Guide to Crochet by Pam Dawson
The Golden Hands Book of Crochet Patterns
New Directions in Crochet by Anne Rabun Ough