The Cambridge Crystallographic Data Centre (CCDC) provides many free programs that can be used to view and manipulate crystal structures. Additionally, they have made a subset of the Cambridge Structural Database (CSD) available for teaching purposes and many educational activities have been created to go along with this teaching subset (see link below). This teaching subset can be freely viewed through the WebCSD interface or can be used in the freely-available Mercury program. (Mercury is avaliable for Mac, Windows, and Linux systems.)
Of the 732 structures in most recent version of the Teaching Subset (01 July 2015), 263 structures contain metals in a variety of structures and in a number of different geometries. One drawback to this dataset is that the structures are not indexed and it is difficult to determine which structures in the database could be useful in teaching a particular topic.
This spreadsheet contains an annotated listing of all of the 263 metal-containing structures in the teaching subset. The code, name, metal center, metal coordination number and geometry, ligands, and general comments are provided for each structure. This document will be a living document and will be updated as the Teaching Subset is updated.
I have used many of the structures described in the spreadsheet in class and as part of exams and homework sets to illustrate many fundamental ideas and concepts in inorganic chemistry. The exercises will be added individually to the site.