I love legs, legs are my favorite workout which is on Monday. While everyone else in the world is doing chest on Monday I am working Legs. I have also learned a lot from doing the traditional leg workout and balls to the walls attitude.
Here is an article that I looked at some time ago. its actually a good read.
7 "Classic" Exercises You Should Avoid | FLEX Online
I have seen too many of my friends end up with back problems from squatting. I learned from their mistakes and do not squat like I used to anymore. Free squats is something I don't do anymore, I either use the smith machine or just machines designed to hit the quads.
My ego still gets the best of me at times and I will squat 5 plates on each side, but that is far and few. All my reps for legs go like 15-30 reps, I don't do any 8-10 reps anymore unless I am squatting 500lbs (ego as I previously said). It really does feel good to squat like that especially when no one else in the gym has any legs.
But as you get older, you truly get wiser when it comes to working out. The last person I saw squat 405 in the gym doesn't do it anymore, he hurt his back.
This is what I basically do for quads now, I change things up to keep it interesting.
Leg Ext: 3x20
Upper Quad Leg Ext: 3x15
Smith Squats: 3x15
Horiz Leg Press: 3x25-30
then hamstrings etc...
I don't train with the guys anymore, I train with my wife so I have to keep the weights not TOO heavy. That keeps me with good form and no ego comes into play.
I forgot to mention that all my leg workouts are so intense, that after I am finished legs I can barely walk out of the gym.