20 rep squat
Whe I first started training squats I did them with great success. It is a very difficult method of training in that it takes full commitment to that one set. SuperSquats is the book that outlined this program for me. It advocates taken a weight you can do for 10 comfortably, and doing it for 20. Every week/session, you add 5-10lbs and repeat. If you are able to keep this up for any period of time hitting your reps, your strength and muscular endurance will go up. I now personally use a Rickey Dale Crain program, but did see great results with the 20 rep program.