Update May 2009: The Las Vegas casinos, which are suffering a huge downturn in visitors, would happily welcome your attempt at our most desperate strategy to raise quick cash, gambling.
Please understand that this is our #1, most desperate way to make some quick cash, and only applies in this situation: you have some cash, but not enough, and MUST have more within a very short time or your life will fall into ruin. When you've exhausted every other possible avenue, only then does a reasonable man consider the casino.
Why is this our most desperate? Look at Las Vegas. Those beautiful building don't grow in place; they represent the house's advantage. Understanding this, what is you best play? If I were in this situation, what games would offer me the best shot at winning enough to save my butt?
Games I would avoid: slot machines, roulette, and other games that are 100% luck. The house advantage is considerable and unalterable. I would also avoid games in which I compete directly against other betters, such as poker. I'm not an experienced player, so the odds would be heavily against me.