I've been trying to get a good grounding with Regular Expressions, and am looking for a single book to do so. I've been going through Amazon.com's listings on this subject, and I've identified a few possibilities, but am unsure which would be best for a C# developer who can write very simple Regexs, but wants to learn more. On a scale of 0-9 where 0 is knowing how to spell "Regex" but nothing else, and 9 where I could write a book on the subject out of my own head, I would place myself at 2. Which of the following would be your choice:

• Mastering Regular Expressions by Jeffrey E F Friedl
• Regular Expressions Cookbook by Jan Goyvaerts and Steven Levithan
• Sams Teach Yourself Regular Expressions in 10 Minutes by Ben Forta
• Beginning Regular Expressions (Programmer to Programmer) by Andrew Watt
• Regular Expression Recipes for Windows Developers: A Problem-Solution Approach by Nathan A. Good
• Regular Expression Recipes: A Problem-Solution Approach by Nathan A. Good

Now, according to Amazon, "Regular Expressions Cookbook" (REC) above is rated the highest according to user ratings, but only based on 20 reviews. The first one, "Mastering Regular Expressions" (MRE) is rated second based on 140 reviews. This alone suggests that MRE might be by far the best one. But is it best for a relative beginner? Would I perhaps be better getting "Beginning Regular Expressions" (BRE) instead, to start with?

Please help me resolve my confusion!