What is the emotional appeal of the trinity? I have spoken to many who believe in the Trinity. I many times try to present the view the Jesus is the second greatest being in the universe and that he was created by his father Jehovah God. I also say that we should have faith in Jesus and his ransom sacrifice. He deserves our love and utmost respect, but that we should only worship Jehovah the God that Jesus prayed to.

I understand why someone wouldn't believe this is true, but I am less sure why someone would get upset about it. I get the feeling people love the trinity. Is there something about the trinity that has an emotional appeal to it?

Sometimes I try to pose a hypothetical and say "Imagine it were true that the trinity is false." Even if they consider it as a hypothetical truth, they prefer the trinity over the alternative. It is this preference that I am interested in. Why the preference? For instance, some have the preference of believing in hellfire because they want there to be punishment for evil. So if they had a choice, in a hypothetical situation, to choose hell over no hell, they choose hell.

p.s. - I don't want to debate the trinity, I just want to understand more the emotion involved.
The simplest answer is that denying the Trinity diminishes the person of Jesus.  There is an enormous gap between saying that Jesus is the Almighty God and saying that he is one of God's creations.  Even if Jesus was God's first and greatest creation, he would still be much less awesome than if he were God himself.  So, it is understandable that trinitarians would be offended by someone who degrades Jesus from God to a mere creation.  The person of Jesus Christ is, obviously, central to the Christian faith, so to differ in such a large way on such a central belief is, in the mind of many, the height of heresy.

Secondarily, trinitarians often believe that the sacrifice of Jesus on the cross for our sins was only effective because he was God.  People holding to this view would argue that salvation for the world could not be achieved by the death of a mere man, even if he was a sinless man.  People holding to this view would therefore be further offended by a unitarian* because, in their mind, the unitarian would be endangering the souls of anyone that he might convince with his heresy.

* In the lower-case, historical sense of the word (i.e. non-trinitarian)