Blink Brain Break - blink left eye snap with right hand/blink right eye, snap with left hand. This would be a fun activity to use when middle or high school kids need to recharge in the middle of class.
20 Brain Break Clips: Fight the Fidgeting! by Bevin Reinen - Videos sure to get your students (and maybe even you) moving and grooving! (Links to 40 more Brain Breaks clips to use in class as well as holiday clips.
The Macarena is simple for even very young kids to do, and this Alvin and the Chipmunks video version is actually appropriate to play in class.this video has no actions, just music = teacher, be prepared to bust some moves!