I remember the STOC/FOCS bibliography that David Johnson compiled in mid 90's (pre-web). It had a lot of interesting "top-k" lists. One list remained on my mind: authors with most number of single-authored STOC/FOCS papers. Andy Yao topped that list, far above the rest.
How does one measure the impact of an author or a publication? The h-index aims to improve over raw counts of papers or citations by combining both, but considers authors in isolation and does not consider collaborations. My coauthors and I have been playing with extensions that "socialize" the h-index. The main idea is, a paper by authors (a,b) should count to the social score of a if it is one of the top papers of b. Now, what is a top paper, how to extend this to multiple authors, etc. are addressed in our paper that also has empirical results contrasting the solo h-index vs social h-index.