The top 10 most cited papers
I've used the tool Publish or Perish to search through 1000 academic papers on Google Scholar that have the term "Service Design" in their title. I've then listed these papers by their number of citations. Here is the top 10 of the most cited Service Design academic papers per year:
This is service design thinking: Basics, tools, cases, which is one of the most well-known books on the topic of Service Design, with 2581 citations per year.
How to design a service by the mother of Service Design G Lynn Shostack with 1885 citations per year.
Service design for experience-centric services with 1385 citations per year.
The service concept: the missing link in service design research? with 1290 citations per year.
Benefits of co-design in service design projects with 894 citations per year.
Multilevel service design: from customer value constellation to service experience blueprinting with 865 citations per year.
This is service design doing: applying service design thinking in the real world, the follow-up to the book that is in the top 1, with 839 citations per year.
Service design: From insight to implementation, the book that brought me to Service Design, with 684 citations per year.
Customer experience modeling: from customer experience to service design with 570 citations per year.
Human issues in service design with 414 citations per year.
A little note about that top 10
I've removed SOA principles of service design (the Prentice Hall service-oriented computing series from Thomas Erl) with 2126 citations per year, from the top 10 as this paper is about service-oriented computing platforms. The term "service design" is also used by in IT for ITIL Service Design which has the same name but isn't the same practice
Go through all the data
I've exported all my search results in a spreadsheet that you can copy or explore if you want to go above the top 10 most cited Service Design academic papers. I haven't sorted out all the 980 academic papers, so there might be more that are about "ITIL Service Design" and not Service Design.