You can see one of my favorites and strongest workout for leggs. it develope a lot of strenght and size... http://www.professionalmuscle.com/forums/showthread.php?s=&threadid=2112
Other routines are 2 supersets of legg extensions with squats in the smith machine or hack squat or 2 supersets of leg extensions with legg presses.
One of my favorites is a 3 set of leg extensions, leg press and squat in the hack squat without rest with all the weight you can do and all exercises to real failure after a warmup with leg extensions to real failure too..
.......There is no space for the littles !!!!!!!!!!!!