Not me, but I know a man who did ....
In Vegas a couple of years ago and me and my Father in Law were walking through the Venetian which he needed to stop for a breather. Put $1 in a slot. won $900.

gallery.me.com/gregmvf4/100026/DSC00454.jpg?derivative=medium&source=web.jpg&type=medium&ver=12645086680001

Next day we were leaving, so wanted to kill some time before leaving for airport. I lend him $10, $5 of which he puts in a slot. Nada. Next slot also gets his (my) remaining $5. Machine mongs out. Starts playing 'You're in the money' ... $3000. Cart and 2 operatives turn up, and he has all sorts of stuff to fill in - basically he had to get an IRS number to be able to claim the money, thought we were going to be too late for the plane. After we're done, Floorwalker resets the slot, and asks us to play a single spin he'd put on it as a credit as nobody would play a machine showing a win.

Father in Law taps 'Spin' as we walk away. Another $1000. Floorwalker/cashier with cart give us heavy side-eyes as neither had ever seen it happen.

Wouldn't let me take photos as not allowed (I got bollocking for the one above), but I shit you not ....
(Captain Dispensible, Thu 28 Apr 2011, 17:54, Reply)