I got an XBox (not 360) and a graphics card for free because the people checking me out were morons.
For the graphics card, it was a cheap little $99 one (didn't feel like spending A LOT of money, now I wish I had since I got it for free) and some various cables. The cashier just forgot to ring that one up and it was super obvious about $99 was missing too. I felt a little bad about that one but Circuit City has screwed me over in the past plenty of times so it equaled out.
And before you call me a jerk, I even asked the cashier if that was it but she was too busy trying to sell me an AOL account to notice she fucked up so her own fault.
For the XBox, I decided I was going to buy an XBox, two games, the really nice monster cables, and an extra controller or two. The Best Buy cashier rung me up, gave me the total and it was something really expensive. I know I was going to be spending a lot so I didn't pay a lot of attention to the total. When I got home and started settings things up my room mate asked me how much it all cost.
I tell him (I forget now, it's been a while) and we both kind of give each other funny looks because something definitely wasn't right about that-- about $250 was missing there. I dig out my receipt and they had completely forgot to scan the XBox. 
