Back in the early 1980s, there was this Japanese guy who had tremendous quads. All he would do was high reps on front squat with 135. He would do fifty reps for three sets starting out with a couple of warm-up sets with 115. No leg extensions or anything. Just front squats for his quads.
Wilf Sylvester won the Universe doing body weight squats, leg extensions and leg curls. He use to do the usual barbell squats, hacks, leg extensions, and leg curls. For his short man win in 1975 he did 400 reps with no weight. He said it cut up and pumped his thighs.
Was the Japanese guy a known name? I'd like to see a picture. I just watched a video of Jay Cutler working thighs. He's still huge at 250lbs. Of course nothing like he was when he was competing. The highest he went with barbell squats was 205 lbs.