These days I don't buy many raw cards. But in 2006 I bought a raw T206 Bresnahan for $63:
After I got the card in the mail, I started to get excited, it had much sharper corners than I had previously thought, and no creases. A few years later, in 2008, I had it submitted, and it came back from SGC in a 70 holder:
Not Bad!
Of course, everyone has a story of getting burned buying raw cards with defects not described in the listing, etc... but I thought it would be fun to start a thread for anyone to post their "raw card success story"...