This is a great question.
I personally enjoy the book of Jeremiah... just because the book talks so much about the relationship between Jeremiah and God (and my personality is similar to Jeremiah's--moody and messy, confused at times, but passionate)--for instance, some of the things I love in that book are instances such as God telling Jeremiah to go down to the potter's shop to get a better idea of God's heart towards His creations... Jeremiah's frustrations and feeling down about his calling and God's answers to those feelings... the opposition that Jeremiah faced, even when he did not outwardly know it (when God told him, "Your friends and family are smiling at you and holding out their arms, but in their hearts, they plan to kill you."
I love that Jeremiah's relationship with God is so honest, real, and at times, heart-wrenching--so very much like my own.
It's so hard to pick just one area of the Bible, but I also love passages like Isaiah 1:18 "Come now, let us reason together"--to me, that is God always looking at us with welcoming arms, encouraging us to come and talk to Him about ANYTHING and EVERYTHING we have on our minds... NOTHING is to frivolous, small, or even shocking for us to talk to God about, which is one of the things I love most about Him.
And I am always touched by the raw emotion of Ezekiel 18:31: "For why should you die, O House of Israel? For I have no pleasure in the death of one who dies," says the Lord God. "Therefore turn and live."
To me, this last passage is like someone who is pleading with their friend or family member over a bad choice/habit/addiction they keep going back too--you can hear the anguish in God's voice, because even though we turn from Him again and again, He is anxiously awaiting for us to have a change of heart and repent so that we can walk with Him again.
We truly serve an awesome God!