I have successfully completed reading the Bible in 90 days. It was difficult at times, but absolutely worth it. The main thing that I learned is that when you put the effort and time in, God will reward you multiple times over. I like to think of it as an investment. The more time I invest, the greater rate of return I receive. Or think of it another way: that which you sow, you will reap.
Prior to this endeavor, I had read much of the Bible including the entire New Testament, but never straight through from beginning to end. Reading it in order gave me a much better context in which to place what I was reading--especially in the Old Testament.
My favorite books of the Old Testament were Exodus and Numbers.
My favorite gospel was John
My favorite New Testament books were Acts and Hebrews
Books I struggled through were Isaiah and some of Paul's epistles.
I thought maybe Psalms or Leviticus might trip me up because of their length and rigidity respectively, but I sailed through them without problem.
My favorite characters were Moses, Joseph, and Daniel.