Yesterday’s model was the simplest Archimedian solid with square and triangle faces. Today we have the simplest semi-regular polyhedron with square and hexagon faces, the truncated octahedron:

STL file: snap-tile-truncated-octahedron.zip
Tinkercad link: https://tinkercad.com/things/l19z2AjEssx-tiles-for-truncated-octahedron
Thingiverse link: http://www.thingiverse.com/thing:185859Settings: The tiles are optimized to work with the low/.3mm MakerWare setting on a Replicator 2.