Busy Teacher - Huge canon of worksheets that covers grammar, writing, reading, listening, and more.
ESL Flow - Find material on EFL lesson plans, speaking materials, worksheets and more.
Figure This! - Online challenges you can do with your family at home. All math related.
Laura Candler Teacher Resources - Mix of work sheets and links to other sites. More of a link site but lots of good stuff there
Lesson Plans.com - Tons of material regarding lessons, work sheets and rubrics. It’s free but hard to navigate
Super Teacher Worksheets - Tons for k-12. Lots of Math, Grammar, Ready/Writing.
Teacher Planet - Big number of worksheets. Some are organized by month to month themes.
Teacher Vision - Number of Classroom Management tips and other great lesson plans and printiable work sheets.
Teachnology - Lots of resources for work sheets, lessons, and rubrics. It’s fairly basic but offers some good material.