I will not make the case that God deserves the praise and honor he demands because he has created a beautiful world (take a look at butterflies, flowers, tropical plants--and remember that the creation is under a curse because of the fall of mankind, so imagine what it was like before), or because he has given us existence and the free will that we so sadly misuse, or that he has given us a solution to the evils we create by misusing that free will (that's Jesus, in case you aren't clear).
In my view, the reason God demands that we worship, praise, and serve him is to get us out of ourselves. God does not need praise or anything else. As the creator of the universe, he's kind of set, having everything he could ever need. But he loves us and wants what's good for us. And since we, as a result of the fall, in which that Eden couple believed a shady stranger they had met for five minutes instead of their creator whom they had known for awhile--since, we, as I say, have brought about calamity on the world by abusing our free will around those who promise paradise, God wants us to remove our focus on ourselves (wanna talk about me, I, mine, my) and shift it to something else. And since he picked himself, the fit is natural. Creator of wonders, giver of life, and savior from sin--yes, worship him and realize that life is not all about you.
Yes, it turns out that many people have it backwards. They focus on themselves and act selfishly, and when they fail to find happiness, they think, "I need to think about myself more," God wants us to realize that happiness comes from giving to others, thinking about their needs instead of your endless wants, and caring for those who live blindly and mistakenly in this hurting world.
The things that God demands--belief, trust, worship, service--are the things that will make us happy and stop the individual pursuit of our own earthly Utopia, a pursuit which has always resulted and always will result in failure, misery, and suffering. More than that, fulfilling God's demands heals our souls and brings us joy through the proper focus of life.
Ask yourself, of all the people you know, how many of the proud ones are genuinely happy? And now how many of the truly humble ones are genuinely happy? Like it or not, the road to happiness is paved with humility.
Humble yourselves in the presence of the Lord, and He will exalt you. --James 4:10 (NASB)
You younger men, likewise, be subject to your elders; and all of you, clothe yourselves with humility toward one another, for GOD IS OPPOSED TO THE PROUD, BUT GIVES GRACE TO THE HUMBLE. Therefore humble yourselves under the mighty hand of God, that He may exalt you at the proper time, --1 Peter 5:5-6 (NASB)