How to describe my favourite scientific publication? And why I have to do that? I recently obtained my degree and I am applying this period for PhD studies  in order to start next year. In one graduate program where I am applying they ask me to give details about my favorite scientific publication and the reasons why I choose this publication.

Honestly, I found this question harder than any other (describe my research experience/research interests etc.). I have research experience and a paper (first author in quite good journal), I have read quite a lot papers in the last two years however I can not say "This is my favorite publication" only a "review" paper which describes the achievements of my field in the last decade and the future goals.

Is a review paper a good choice for this kind of question? What should I to in this situation?
I think purpose of that question while applying to graduate program is to check your judgment or thought process. It will be similar to writing statement of purpose (SOP) where you try to justify why do you choose any institute/program/career etc. I think, any paper (research or review) is fine as far as you give reasonable answer to their question about "why do you like that publication". 

There might be many different answers to that questions, One might like following things from that paper 


The way research has done
The way authors have interpreted results
The way connections have made to other problems
The way they have formulated model from existing information (This is generally done in reviews)
The way authors has provoked future questions 


Most important thing you should mention in your answer that how this paper has helped you in any way. For example, one might say, I liked the way authors have used very general methods cleverly to answer some difficult question which changed your perception about solving difficult questions with simple methods. In case of review, you can say how authors have used many well established and new concepts to make current model. This helped you in understanding some complex concept.