Why should anyone read Bhagavad Gita?

I wanted to open up the discussion as to why should one read from Bhagavad Gita? Is it to learn from the teachings to live a happy, peaceful and purposeful life? Please send in your comments.

I would like to include a stanza from Bhaja Govindam composed by Adi Shankara.

bhagavad.h giitaa kiJNchidadhiitaa
gaNgaa jalalava kaNikaapiitaa .
sakRidapi yena muraari samarchaa
kriyate tasya yamena na charchaa .. (20)

Let a man read but a little from Gita, drink just a drop of water from the ganges, worship murari (govinda) just once. He then will have no altercation with Yama.

Well, I am not sure about water from the ganges :-) May be opening a bottle of AquaFina might be better!

Have a wonderful and a happy day !