They have beaten Hong Kong which after WWII was way more economically advanced than Singapore and many other Asian countries during the 50s because of their status as a British Crown Colony. Heck, the Singaporeans are proud because they beat Hong Kong recently and don't even bother about the news that they surpassed Malaysia.

Hong Kong was their rival, not Malaysia.

Read the article.

Like I said, you are looking in the short term. No matter how much oil Brunei has now, it will run out. The article states that more than 90 percent of Brunei's economy is oil based. They almost have no industrial base and no knowledge worker base. Their people are not productive and I think depends on the oil money their government hand to them. In fact, the article states that the government even embarked Islamification policies recently that drives even more smart and productive people out from the country. Their attempts on diversification has failed repeatedly.

They are in fact, worse than the UAE. At least Dubai is more modern than Brunei and embarked to a more successful diversification by attracting talent to go there until the big bust of 2008. Brunei, the opposite is happening.

Sure, Brunei looks very gooding now, Tell me. Would you stake your children's and their children's future on a country like Brunei?

Talking about economic wise, there is no doubt Singapore is better than any other ASEAN countries. Is it the best place to live? That is a BIG NO!! unless u have a lot of money. A lot of Malaysian work in Singapore coz its lucrative but y come back to Malaysia? Y not live in Singapore? All this Singapore is the best la.. Not sure if half of Singaporean even know to sing their national anthem.
Singapore is rich in the first place is because of its strategic location and the size of the country. From there, they slowly build their economy. Their port is their starting point since they dont have any natural resources.

Well, that's wat i got from my Malaysia Law class in Uni. Some how it got side track to how Singapore got separated from Malaysia. And my prof was a thai national. lol.