Ever wonder why God wants us to obey Him? What exactly does God receive from our faithfulness and obedience? We say that we want to please God and do so by avoiding sin or making a sacrifice in our service to others but how does our improved morality or increased service advantage God? He doesn't need anything nor does our goodness add any advantage to Him—He's above it all anyways.
I believe the answer to this question lies in His character of love. John says that the defining element of His nature is love (I John 4:16) and this is the first clue that reveals the reason He is pleased when we obey. The second clue is found in Genesis where Moses writes that humans have been created in the image of God (Genesis 1:26). The final insight is the fact that disobedience is the cause that now separates man from God and alters his original God-like nature (Genesis 2:15-17).
When we put these together we realize that when man obeys God it means that He is seeking to become like God as he was first created to be before sinful disobedience marred his likeness of the Divine. This, in turn, pleases God because it means that man is positioning himself (through faithful obedience) for blessings which God, in His love, is eager to provide for those who believe and obey Him. (Ephesians 1:1-14).
So, what's in it for God when we obey Him? The short answer is that our obedience gives Him the opportunity to bless us in love, and blessing us pleases Him.