Why it's better for your bankroll to stay away from volatile machines and stick to those with a higher hit frequency...
1. You can play longer
2. You end up having more money leftover
3. You don't want to seriously injure others or the machine
Volatile Machines such as: Wizard of Oz, Buffalo, Wicked Riches, Price is right and i'm sure there are others.
You are honestly better off buying a lottery ticket. DISCLAIMER: Lottery is most likely less fun.
$1- Top payout 175 million
Volatile slot machine:
$1 NON PROGRESSIVE- Top payout roughly $5000.00
Even progressives usually max out at around 3 million with exception of megabucks. They also will cost you more than $1 a try.