Squats - good
If your knees are making noises, but with no pain then you should be ok.
Leg press is good if you can get to a machine.
Lunges, with bar/dumbbells
Be careful of straight leg deadlift, good exercise for hamstrings, but very dodgy if you either have a weak back or aren't doing them properly.
Calf raises on a step, one leg at a time to maximise your bodyweight, or/and with dumbbells.