I suspect that the voting results on the books of the bible ranking on the blog indicates at least the following:
1) Large Lutheran readership for whom the influence of Romans on Luther remains important.
2) Just slightly lesser recognition that Exodus is the linchpin of the OT, partially because it is the story of the liberation of Israel from bondage, but also because it is the lense through which we read much of the rest of the Bible.
3) A bias towards the more theological of the gospels- John. I also am biased in this direction.
4) At least some fleeting recognition that the Psalms are the Scriptures in miniature.