I read Left Behind ten or eleven years ago (shortly after converting to Christianity, I think). I read the second and third book in the series, and part of the fourth, before stopping. I quit because I realized the first of three things I now know about the series. To wit, why was I reading fiction based on the Book of Revelation when I hadn't read the Book of Revelation (or finished reading the Bible) yet? That was what got me out of reading the Left Behind books.
Second, as a reader and fairly skilled writer, I know the quality of writing in this series is mediocre at best. The prof in my third creative writing class made the same observation--"they're poorly written."
Third, the assistant pastor of my church recently described these books to me as "spiritual candy" (as in junk food) and "one guy's version of [what might happen]." More recently, I learned that the Rapture will not occur until after the Antichrist reveals himself and claims to be God (1 Thessalonians 2:1-4). I have no idea how, in light of that passage, LaHaye believes the Rapture will occur first. I am annoyed at the mistaken ideas the books planted in my head before I started regularly attending church.
Don't rely on Left Behind and its sequels for prophecy. Stick with the source.