Here are some Wiki pages (and my role in them) to which I have made significant contributions :
Halldór Laxness—about half the content and most of the structure and references.
Wanda Gág—most of the content and references and about half of the structure.
Pascal Pinon—most of the content, structure, and references.
Frank Lloyd Wright—a tiny amount of content, significant work on structure.
Working on Wikipedia has helped my discipline as a writer, especially in referencing. I haven’t had too many problems with edit wars, most of my subjects of interests are pretty low in importance to trolls. It is a pretty nerdy pursuit, but does give me some satisfaction to see a page grow from a disjointed mess into something better than what a “regular” encyclopedia would produce: compare the Britannica articles on Laxness and Gág to the above-linked Wikipedia entries for two examples.