Can anyone direct me to a listing or source that shows who are the largest or Top 50 etc employee benefits consultanting firms and their size or revenue?

Are you looking for (a) those we consider the top 50 consultants (in which case I might overcome my modesty and list myself and a few others) or (B) a listing of consulting firms in the order of their employee benefit consulting revenue?

While I do share your "unwritten" sentiment that quality does not mean large size, I find it necessary to use a standard unit of measure... Revenues.

GB, this list's a bit dated (1998?), & broader than your specific request, but includes several of the biggest benefits consulting firms:

top 50 consultants' list

Most lists I see are self-reported (BI's list, for example) so results are akin to a survey vs anything "auditable". Another challenge: finding breakouts of revenues for benefits consulting specifically, vs all other advice-giving activity.

Good luck!