It's a simple question, but at the same time it asks so much. In fact, as I pondered it I went back and forth several times. My first thought said "Creation, of course! Think about all the things we've made that wouldn't exist without humans!" and immediately that turned to "Except how many things have been destroyed in the name of that creation?"
I'd think many people would say that human nature is to build through ruin. We are equally 'skilled' at both concepts. Yet I think that this is a simple way to avoid the question altogether. I can't tell you how many books I've read and movies I've watched that asked an abstract question in the beginning only to answer it by saying "Humans are both good and evil" or "Love is the true path". This sort of answer is cliche, and while it sounds profound at first, it isn't, in truth, an answer. You cannot choose by saying something other than 'yes' or 'no' when asked a direct question.
So here is my stand. I'd say humans are better at creation. It is the nature of all living things to create, after all. Humans, like all creatures, have the physiological need for food, water, and shelter. Nowhere does it say we must destroy in order to make that happen. We must kill or harvest to eat, but we are not destroying, we are not destroying that substance as we eat it.
One can argue that humans destroy because of the loss of the planet's natural resources. I won't deny that deforestation and carbon footprint and all of that are real issues, but destruction was not the goal of humans when these problems occurred. We take things to create, and create we have. We destroy things in the process, but time erodes all things in the end, anyway, so it doesn't really matter.
Everything we destroy would end up gone regardless of what we do. We can mourn the extinction of species due to the harm we due to the planet, but I think most often all we really accomplished was the inhibition of the generation of new creatures. Poaching and malicious action aside, deforestation doesn't directly kill creatures, it simply makes it harder for them to reproduce. We can't be sad for all of the creatures that weren't born because of that, because they never truly existed in the first place.
Humans are creative things. It would be hard to argue that putting humans on other planets would be a feat driven by creation. I can't think of anything that points towards humans being on that side of the spectrum than us creating something where nothing could have possibly existed before.
Beyond life and death, humans create on a daily basis. Beyond even drawing or writing, thinking itself is creation. Humans are creators, and even though the cost of some creations can be great, anything that is destroyed by us is merely a side effect of that process.