I like to see people avoiding a routine- doing a specific split every week is OK, but the more you vary each workout, the longer you stay in the "adaptation" phase of muscle development.
Here's a short list of exercises to make several different leg workouts. Choose one from each group, and change your list every leg day. This template goes from biggest muscles to smallest, so that you are doing the most difficult exercises when you have the most energy to burn. Of course, if you are familiar with different exercises, you can use this template to help you with ordering.
Exercise 1: Compound Leg Movement
Bench Squat
Leg Press
Dumbbell Squat
Step Ups
Exercise 2: Quadriceps
Seated Leg Extension (Single or Double Legs)
Standing Leg Extension (on cables)
Standing Lunge
Walking Lunge
Exercise 3: Hamstrings
Prone Leg Curl (Single or Double Legs)
Standing Leg Curl (on cables)
Seated Leg Curl (in gyms that have this machine)
Bridges (Single or Double Legs)
Exercise 4: Adductors (Inner Thigh)
Adductor Machine
Cable Adduction
Exercise 5: Abductors (Outer Thigh)
Abductor Machine
Cable Abduction
Exercise 6: Gastrocnemius (Upper Calf)
Standing Calf Raise (Single or Double Leg)
Calf Press on Leg Press (Single or Double Leg)
Exercise 7: Soleus (Lower Calf)
Seated Calf Raise
Bent Knee Calf Press on Leg Press (Single or Double Leg)
When doing calf press on any leg press machine, make sure that either the seat adjustment or the safety stop on the sled are set up to limit how far the sled will drop if your feet slip off the platform. If you cannot adjust the machine so that your legs are mostly straight when you get into position (before lifting the sled off the safety stop), then don't do this exercise.
Why? If your feet slip and that sled drops to the lower safety stop, your kneecaps are going with it. I've seen pictures of this, and it's not pretty. I've also seen two close calls in the past year which resulted in pretty bad bruises and scrapes, but luckily nothing orthopedic.
Cameron