The most I’ve won is $495. I remember the exact amount as I thought I was shit hot. Mind you I think just about everyone loses over the long run, except the casino, of course.
I once got up to $300 playing blackjack on a $100 stake. OTOH, these were Zimbabwean dollars which were about 20 to one USD at the time…
I’ve found it easiest to win playing blackjack, but one has to have the discipline to walk away from the table once you’re up by a decent amount. Roulette, craps, don’t play 'em, don’t like the odds. I enjoy slots but never expect win anything at all.
Once while driving to California, stopped in Vegas for lunch. Walked in the door of the Nugget, put a quarter in the first slot machine I saw. Won 50 cents. Having doubled my money, I turned around and hauled ass out of there. Yeah, boring, I know, but at least I have money for my other vices…
I won just under a dollar playing the nickle machine. Of course I wasn’t of age, at the time. I was only 15 or 16, but I had a beard and long hair (both my own). 
I was shitting bricks, though. I don’t recommend it. The girl next to me was carded, and she was 27. I thought, “But hey, she looks young.” Then a woman came up behind me. I’m shaking as she taps me on the shoulder. “What?!?” I shout. She asks if I would like a drink. I say yes, a coke please. 
Of course, now I am actually of age (as of today). I don’t know if I’ll go to the casino. Now I’m a university student, so I can’t afford it.