The best filler depends partly on filler and partly on your doctor
The main differences between filler types are consistency and longevity. While some fillers are definitely better placed deep into the skin because of their thickness like Radiesse, which is not generally used in the lips for this reason, often doctors have personal choices in the fillers they like to use in different places. In our practice, we use primarily hyaluronic acids, a gel like substance, whereas Radiesse (calciumhydroxylapatite) has a consistency of paste.
Often we use the hyaluronic acids for a patients' first treatment simply because they are softer and gentler. For patients who want a longer-lasting filler and want more "umph," we use Radiesse because it lasts longer. However, it tends to swell more and you may have a tad more bruising.
Another difference between hyaluronic acids and calciumhydroxylapatite is that hyaluronic acid may be reversed with an injection of Wydase, while calciumhydroxylapatite may not.
Much depends on your specific anatomy and aesthetic goals
As you may well know already there are many options available when it comes to cheek augmentation. In general techniques used can include implants, surgery (mid-face lift), fillers or fat injections.
The technique used will vary from Patient to Patient based on the unique anatomy and desired goals of each individual. When it comes to fillers the choices include using a non-permanent (short acting) or permanent (long acting) product.
Restylane, Juvederm, Evolence and Ellevesse are the more commonly used fillers for cheek augmentation. They are all non-permament and vary in how they work and how long they last. Radiesse and Scupltra are also used but have a different mechanism and duration of action (long term). I personally do not use much Restylane for cheek augmentaion as I feel it doesn't provide enough "bulk" to help in the cheek area (better suited for the lips or under the eyes). The others mentioned have a little more "bulk" to them and would be a very reasonable and effective option.
One important concept for you to be aware of : cheek anatomy is highly variable and in some cases a filler may not be the best choice to achieve the goals you desire. Important to have an experienced Physician go over your anatomy and goals with you so that an effective and worthwhile procedure is arrived at.
Fillers for Cheek Augmentation
Your question indicates you are aware of the many non-permanent fillers for cheek augmentation. The material selected depends on the appearance of your cheeks, the reason for the lack of projection, and the experience of your physician. For example, I prefer Radiesse for non-permanent cheek injection in most patients. If a patient has the loss of facial fat secondary to being HIV positive, I think Sculptra is a better choice. Success depends more on technique than product.