Other contributors have said "What foods can get mold on them?" is the same question as "What type of mold grows on food?" If you believe that these are not asking the same thing and should be answered differently, click here
I think bread molds the fastest because I had bread in my house and it got moldy within a couple weeks. If not then I think vegetables, specifically tomatoes, mold a close second.
Nearly all foods today will spoil given circumstances like a warm moist environment. Mold is a bacterial culture that has grown to such a size to be visible. The only known food that will never spoil...