I just completed reading Misquoting Jesus by Bart D. Ehrman. In a word - fascinating.
It's not surprising that the words we read in the Bible today are different than the words originally captured back in the 1st, 2nd and 3rd centuries A.D. - or even more recently than that. It's a well-known fact that these words have had to endure through several translations from one ancient language to another, and the vagaries of being hand-copied by hundreds, if not thousands of scribes over the centuries until the invention of the Gutenberg press in 1450, so changes are not only expected, they are inevitable.
What this book does is provide a history of that progression and many examples where ancient writings and the currently accepted version of the New Testament (the book focuses primarily on the new Testament) disagree. The author then explains the methods used to identify the inconsistencies and the various approaches taken to try to determine how and why the changes occurred, and which version best represents the author's original intention.
What I found most interesting is that this wasn't a simple exercise of establishing time lines from which it could be determined that the oldest text was necessarily the correct (or more correct) one. Manuscripts would leap-frog each other, and in some cases, more recent texts would be based on much older originals, now lost.
Equally fascinating was the discussion of why scribes might change the text they were working on at the time. Certainly there were situations where simple transcription errors could result in significant changes being made to the message, but equally there were cases where changes were made intentionally, either at the behest of the patron (whoever was paying to have the manuscript transcribed) or the scribe himself, based on his own, personal beliefs and their cultural or political environment at the time.
All in all a very good and interesting read for anyone (Christian or not, religious or not) who has any interest in how the word of God, as represented in the New Testament of today, came to be.