Blackjack?
Blackjack, roulette, poker, slots, all around. Play conservatively, never lost more than $500 total on vacation, have usually won more than that. Usually I do very well at blackjack, playing conservatively. That means steadily increasing my bets during winning streaks and not pulling out too soon. If it's a losing streak get out immediately and find another table or dealer. My wife likes slots more than tables so I join her at that, and usually win. Same principle, if the machine is losing more pulls than winning get out immediately and find another machine. If you're getting a lot of play (meaning enough wins to keep playing without putting in more money) then stick with the machine and increase bets until you're at max bet. Since we like playing for fun and not for the money, we stick to the low denomination machines (penny, nickel, dime, quarter) although sometimes we play the dollar slots. We tend to get 2 or 3 hundred dollar jackpots on the nickel and dime slots. Last month we flew across the country with a connection at Las Vegas airport and made a couple hundred each way during the hour we spent there at the terminal playing slots.
Tables are where you can win big amounts. A few times I've started with $20 on roulette and walked away with $400 on wins. We play for fun and not the money. Seems that if you focus on winning money, you'll instead lose.
I have a sister and her husband who lives in Las Vegas. They're poor but living a good life. (Huh?) They jump around on part-time jobs in hotels and casinos, play poker that gives them most of their money to buy meals and pay rent. I don't rely on gambling to get by; they do and they're happy.