Personally if I want to turn a small amount into a quick x profit for fun I do,
10$ into 5-10x I see the most success I have with games like Mines.
I try avoid slot games with low budget, what is your "safest" game for you that you feel lucky on, and have most fun with?
If you say quick profit then it's not longer gambling but a charity, what casino would allow you to make a quick profit from them? it's not designed that way you have to loss, it's normal.
BTW, games that I have played and made at least little profit from without calculating how much I must have lost is probably crash game. it's more of a place where I enjoy (have fun) and also get lucky at times.