Brent Ozar Unlimited's repositories
SQL-Server-First-Responder-Kit
sp_Blitz, sp_BlitzCache, sp_BlitzFirst, sp_BlitzIndex, and other SQL Server scripts for health checks and performance tuning.
sql-server-maintenance-solution
SQL Server Maintenance Solution
BrentOzar.com-Demos
Demo scripts from blog posts at https://www.BrentOzar.com.
Stack-Overflow-Database
Small copy of Stack Overflow database with 2008-2009 data only.