I'm reading a book by T. Boone Pickens The First Billion is the hardest and I heard the same old story repeated. Mr. Pickens, as well as the others mentioned above are similar in that they are all fairly wealthy; but digging deeper, they are hard workers who take big risks and subsequently have reaped great rewards.
When you look at the sorts of things these guys do, it's striking that they are in different industries and have different techniques for success within their industry. A few are crappy leaders (of people), they've all made various and arguably large mistakes. More importantly, however, they also all observe the world around them, seek out opportunities, take calculated risks, and succeed where others are not even looking.
None of them "got rich quick", they moved forward at what some might actually consider a snail's pace. Each tiny step forward, however, built upon previous successes and failures. When studying these guys, the 80's movie The Secret of My Success almost seems to be a legitimate blueprint for success. Michael J Fox's character realizes an opportunity, not because someone approached him and said "here's a great opportunity", but because he dug in and found value and didn't take "no" for an answer.
work hard, take chances, seek value