Student Samples, Grades 7-12
Time For Kids
http://www.timeforkids.com/homework-helper/a-plus-papers/compare-and-contrast-essay
Compare and contrast sample paper.

Houghton Mifflin - Writer's Showcase, Grades 7-8
http://www.eduplace.com/kids/hme/6_8/showcase/7-8/compare.html

ESL Bee
Compare and contrast 'block' and 'point-to-point' writing instruction with examples.
http://www.eslbee.com/compcont.htm

ESL Bee
More compare and contrast 'point-to-point' essay samples:
Cows and Whales
Vacationing in the City or at the Beach
Eating Fresh Foods or Canned Foods
Industrial Engineer or Administrator
Aerobic Training Versus Anaerobic Training
Two Great Mexican Cities
http://www.eslbee.com/comparison_contrast_essays_models.htm