Not sure I can lay claim to the #1 spot on Steve Garvey, considering mrmopar's vast collection and the fact that I'm #3 on the Steve Garvey PSA Master Set (and that #1 & #2 have left me in the dust), but I have a pretty fair collection. Mine, however, is limited to his playing years and pretty much just material that has been, or could be, graded.
Here a link to my PSA-graded set, if you wanna have a look-see:
https://www.psacard.com/psasetregistry/alltimeset/17092