Front squat, over head squat, olympic squat, pitcher squat.
You're RF really doesn't make up much of your thigh, infact, the vastus medialis, intermedius, and vastus lateralis attach high on the femur:
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Are you lacking size in your adductors? This contributes a lot to the girth of the thigh.
Also, the tensor fascia lata and the sartorius are muscles at the top of the lateral thigh.
But still, I suggest you continue to squat, or perform variations of it that place more emphasis on your quads and less on your hips for anterior thigh development. This, however, does not mean you should neglect your posterior kinetic chain (hams and glutes).
Br