All images of crystal structures on this site were generated using the free software package Vesta (JP Minerals).
Having experience with every major structure visualization program Vesta has proven to be the best for working with most compounds (excluding proteins). It is lightweight, fast, and multiplatform (OSX, Windows, Linux). The leading subscription-based counterparts tend to be bloated and slow in comparison. Vesta can also display volumetric data (VASP, Gaussian, Win-GX…), a rare feature for a structural visualization program with such an intuitive user interface. Finally, if you find yourself scanning through hundreds of cif files from multiple databases (CSD, ICSD, AMCSD…) no program is faster at setting the custom cell boundaries, bonds, and polyhedra need to make sense of a structure.