While there is no objective way to say which human right is the most important, I would argue that the right to life is the most important human right.
Without the right to life, we would have no other rights. Imagine, for example, that you had the right to freedom of religion, but not to life. You would be able to practice the religion of your choice, but that right could easily be taken away simply by someone killing you. If we do not have the right to remain alive, we do not have the ability to enjoy any other right.
Similarly, I would say that the right to be free from slavery or arbitrary imprisonment is the next most important human right. If you are a slave, you do have your life, but you have very little else. It will be very hard to enjoy your life if you are enslaved.
After these two rights, the question becomes much more complicated. Once you have the right to live and the right to be free, which right is the most important? It is very hard to say, for example, whether freedom of speech is more important than freedom of religion. I think I would argue that the right to participate in your government is most important. If people have the right to vote in meaningful elections, they can protect most of their rights through the political process. In other words, if the government tries to take away your freedom of speech, you can vote against the government and remove them from office. This is a good way to safeguard your rights.
I would say that the most important rights are those that protect our life and our basic liberty. After that, I would argue that the right to have democratic control of your government is probably the next most important right. However, it is definitely possible to have a different opinion on this issue.