I'm more or less a PSA registry addict, so I only buy PSA cards. When I get a catalog, I skip the SGC cards.
The one exception would be if it's an SGC card that I can't find in a PSA holder. Then if I win it I cross it over to PSA.
Here is a link to one of my HOF sets:
http://www.psacard.com/PSASetRegistr...t.aspx?s=18882