@akowally,
Most saccos are profession based e.g
Mhasibu-Accountants
UNSACCO-UN Employees
LSK Sacco-Lawyers
Kenya Bankers-Bank Employees etc
"Best" could mean best in terms of dividend payout rates,service,loan amounts,projects e.g land,houses for members etc.
I would advice one that has several "projects" such as land reselling to members,housing projects etc.If you are an accountant Mhasibu is quite good.
Formally employed people often live their employers' dream & forget about their own.