Oh god I've spent a lot of money on Arc Dream stuff ever since listening to RPPR. Whee!
-A Dirty World
-Every Monsters and Other Childish Things book. ALL OF THEM
-Kerberos Club (And by extension, Wild Talents: EE)
-Call of Cthulhu (Though I wanted it before listening to RPPR)
-Masks of Nyarlathotep
-Fiasco!
-The Laundry series
-A few Kickstarters here and there.
-Oh, and Esoterrorists, Fear Itself, and the Book of Unremitting Horrors. I will use Clooties in my game some day!