What are the most fascinating things researchers are working on?

Hi Aya, == Your question has multidisciplinary answers and concepts, because there are hundred of thousands fields of research works or even more due to sub-divisions of each field to get more specialized researchers in those mini-topics to work on and innovate there.
== In the field of medicine, countless of researches were focusing in drug discovery and genetic study to resolve the most commonly known diseases and even rare inherited disorders.
According to Pharmacology, my filed of specialty, scientists and researchers are concerned with pharmacogenetic studies to advance gene therapy, possible natural products to treat most of common diseases, and studying the mechanisms of actions of each disease in different methods and then identify the exact causes behind this illness which will be the key of treatment.
== If you want to search for one topic in medical field, you can choose one of the following engines like: PUBMED, MEDLINE, MEDSCAPE, SCIENCE DIRECT, SPRINGIER LINK and NATURE, you will get surprised from huge numbers of issues and thoughts diversity in those works.
With great hope to get benefit from my answer.
Thank you

The most fascinating things that researchers are working on is the research in the field of innovative technology because of the competitive market of technology.
It is very hard and high resources, skill and time in micro level.

For marketers, the most fascinating things in research right now are rapid changing in consumer taste.
As market in every product getting tough and consumer are getting verity in product with numerous options and knowledge about product.
And the newly emerge "Social Media" has added effective and harder to understand its impact on consumer, which is also under study for marketers.
As they are making much research on it.

The most fascinating things that researchers are working on is the research in the field of regenerative medicine, where they can discover new treatment based on the clinical trials for major diseases such as cancer, diabetes and liver failure

It is hard to answer this question, because each area of research has it fascinating special field of research.
for example, people here is the west spends a lot of money for renewable energy research but at the same time they spend a lot of money on medical research as well.
This because both areas will be helpful and beneficial to humanity.
So, it is hard to favor one research area on another.