Who are the world's greatest investors -- the investment wizards who not only made a fortune themselves but, more importantly, helped millions of people who invested with them reap rich harvest consistently over the past four-five decades?

Coattail Investor, a US-based investment advisor and research firm, made an attempt and picked seven greatest investment icons of all time. There is no surprise in the selection of the numero uno among them.

The 76-year-old legendary investor Warren Buffett, who is known as 'the Oracle of Omaha,' topped the chart.

"A $10,000 investment into Berkshire Hathaway when Buffett took control in 1965 will be worth over $50 million today. By comparison, $10,000 in the S&P 500 would have grown to only $500,000," Coattail Investor stated.

Next to Berkshire Hathaway Chairman Buffett in the list is John Bogle, founder and chairman of the Vanguard Group. Bogle, often referred to as the father of index fund investing (he is the creator of the first S&P 500 index fund), is followed by Fidelity Vice-Chairman Peter Lynch, who was a Fidelity fund manager earlier.

Arguably the world's most famous mutual fund manager Lynch was often described as a chameleon, as he used to adapt to whatever investment approach worked at a given time (growth vs value).

When Lynch started managing Fidelity Magellan Fund in 1978, it had assets of $20 million, but when he retired in 1990, the fund's assets increased manifold to stand at $14 billion.

Julian Robertson, a titan of hedge fund investing, comes to the fourth place in the coveted list. Founder chairman of Tiger Management Corp, Robertson is famous for turning $8 million in 1980 into over $8 billion in the late 1990s.

One of his famous quotes reads: "Our mandate is to find the 200 best companies in the world and invest in them. And also to find the 200 worst companies in the world and go short on them. If the 200 best don't do better than the 200 worst, you probably should get into another business."

Michael Steinhardt, founder of Steinhardt Partner, who ended his illustrious hedge fund career in 1995, a year after suffering big losses, comes next. A $1 investment with Steinhardt when he founded the firm in 1967 would be worth $462 today.

George Soros, founder of Soros Fund Management, who shorted the British pound for a one-day gain in excess of $11 billion, is sixth in the list of illustrious investors.

Soros, who has expertise mainly in currency speculation, was, analysts estimated, earning over $4,000 a minute at a point of time. "It's not whether you're right or wrong that's important, but how much money you make when you're right and how much you lose when you're wrong" is one of his famous mantra.

John Templeton, founder of the Templeton Group and a true pioneer of the global mutual fund industry, is listed as the world's seventh greatest investor.