While it seems that some answers here already provide a good an satisfying answer specifically from a Christian perspective, this question is flawed, and in its current form is not a useful question as the answer is simply "an infinite set of possible reasons".
If that’s the main reason then I cannot consider such an action a proof of divine greatness.
I'm not certain that anybody is asking you to consider that such a proof. However, I am likewise not convinced that it could not be proof. It would need to be first agreed what standards you are setting and why, and you seem to only be either using an invalid standard or one that is subjective.
The question is too generic
You are asking a general question about why some unspecified God (though some examples of possible gods are given) might create a world. Without specifying a specific framework, you allow for any number of potential creator beings, many of which would have unrevealed reasons, reasons which are impossible to ascertain with our limited understanding, or even no reason at all. Divine beings are not subject to using similar thought processes as our own or even dealing with factors of which we can conceive, and so there is no necessity to presume, given your criteria, that there even is a reason we could articulate.
You cannot equate human and divine motives
You also are incorrect in attempting to draw comparisons to certain motivations which humans might have and motivations which divine beings might have. Humans function on an entirely different level. For one thing, we are limited beings surrounded by other similar beings, consisting of material which we did not create ourselves. Attempting to assert ones qualities as being excellent compared to similar beings would likely be short sighted, but this does not apply to a unique divine being with utterly complete knowledge and wisdom, and to things which he created entirely by himself. If a toddler walked around with a loaded gun, he would be dangerous and bad, but if a healthy adult did the same thing, it would be a very different situation, and the distinction between them is only a few years of age, not an entirely different quality of existence.
Furthermore, the concept of whether or not a person or attitude is actually wrong, immoral, or in any way undesirable is often greatly impacted by whether there is a divine being and what his attributes might be and what they might be for us. So, if there were a being which created the world for self-glorification, then that would be just as acceptable a reason as anything. It would satisfy reason and philosophy just fine. It might not make you happy or it might be subject to individual preference, but that would similarly be true with any belief, true or untrue.
Improving the question
One potential improvement, if you were attempting to seek understanding of a particular religious framework, would be to ask the question of a particular religion, or set of religions. For instance "What is the reason the Jewish/Christian God created the world?" or "What are the most commonly understood reasons why Abrahamic religions believe that their God created the world?" Those would allow for the great answers here to be definitive. Or perhaps, you could even ask if there are any common trends among popular beliefs about why popular gods created the world.
However, you seem to be less interested in specific religious positions and more interested in generic arguments related to Theism. In this case, you might consider asking about what is the philosophical value of comparing supposed reasons people believe that gods had for creating the world with values that those people and cultures have concerning valid reasoning. Or perhaps you could question why it is that some people, such as yourself, expect there to be some reason which aligns with your preferences or expectations. After all, if the being which created our minds (assuming a framework such that one did) with reason/morality/preferences, it might be reasonable to suspect that such a being might related his intentions in a way which can satisfy some of those. Either of these could yield some interesting questions and answers.