From now on I'm going to be a little more harsh with my ratings. I figure the following is a decent scale:

5: Excellent! Everyone must read! I probably will again at some point.
4: Very good. I will recommend this to people who like this sort of book.
3: Average. Nothing to really shout about or recommend.
2: Poor. I managed to finish this book, but there were too many flaws for me to really enjoy it.
1: Do not read. Ever. I probably couldn't even finish it.