It depends -- I love the Old Testament stories for the lessons we can learn from them, and I love the Psalms and Proverbs for a lot of reasons. However, I prefer the New Testament for what it means to my salvation -- plus, I'm SO glad we don't have to sacrifice all those animals that God's people in the Old Testament had to sacrifice!!! Eww -- all that blood! I'm so thankful for Jesus' sacrifice once for ALL!
By the way, I just found your blog today -- for your last question -- I prefer the NASV because that's what I've been using for many, many years. I find it very readable. However, I've heard good things about the ESV, too.