I believe my biggest single win was 16K off a £20 bet. I was dealt a pat RF at Phoenician casino long ago when it was part of casino action. It was 2am during their jacks or Better 24 hour wager race, and I only played again because some yankee smartass had decided I had gone to bed and it was worth a shot at a late sprint. Our flags were shown on the scoreboard, and as it ran on EST, the yanks had the advantage of not having to stay up till 5am, and could wait for the Euopeans to go to sleep and take them out right at the end.
It barely registered. I thought I had been dealt a pat ORDINARY flush, and thought the game had gone wrong because the "flush" didn't highlight on the paytable. It took a while for me to register I was looking in the wrong place, and as I looked up, and again at the game, I realised the game had NOT malfunctioned at all
Although my biggest single win, it did not form part of my biggest ever winning session, which was on the AWP slots at Microgaming. It is actually possible that one particular session contained a win bigger than this, but it is not the 6 individual wins I remember, but the fact that I had six consecutive monsters in around 15 minutes that springs to mind. In terms of win as a multiple of stake, this 16K barely features, it being under 1000x bet. I have since had over 3000x bet on the AWP games.
I have screenshots of all these monsters back to 2003 on my PC, so I could order them into absolute size, and size relative to stake. They are also scattered throughout the winner screenshot thread.