While I have my own answer to these questions, and have for a long time, I was initially only going to discuss what these questions might mean to different people. I do like to leave you to find your own answers, as it is both an immensely satisfying project and the only way you will truly believe your own answer. However, I am dismayed with how people often answer this question when they do not agree with me, with money, fame, religion, or power in some combination, so I think it worthwhile to advocate for my own answer.
My answer to these questions was determined when I was in high school, and has yet to change. At that time, I considered the question, "what is the most important thing in the world to me?" The answer that fairly quickly presented itself was the people around me. In some sense, other people are the only things in this world that are real. For example, while a car may exist on a purely physical level as a thing of steel and oil, it is only a construction in our minds that understands that a car is a vehicle. Perhaps more telling is the existence of a book, without our minds interpretation a book is nearly impossible to tell apart from a blank journal, both hold almost exactly the same physical form, but a book can impart so much more to our minds. On the other hand, each and every person you will ever meet, or even with whom you will interact, carries around her or his own mind. This means that it doesn't matter how deeply you consider their existence, they still exist. Which, to me, means that their existence is once of the most important things to consider thoroughly.
This is not to say that money, fame, religion, or power are inherently bad values, just that without including people as one of your primary concerns you dance perilously close to becoming a monster. Without a concern for people, revering money quickly leads to the types of exploitation we see in colonialism or in Enron's treatment of their employees. If you seek fame, but not common good, one might become a cult leader, or the heartless star of a reality show if one prefers to avoid the Kool-Aide. Religion fervency that is not tempered with genuine human compassion can lead to religion violence, something most every religion experiences from some followers, or evangelists whose aid is conditional upon displays of piety from the needy. The pursuit of power regardless of the cost to others paves the way for poster-child evil politicians. I personally consider fame and religion to be among my motivators, but I attempt to always temper my endeavors with a consideration for my fellow humans.
So, go, find what you think is important! Once you do, look for it! But I implore you to place other humans high in your priorities.