NEW YORK (CNNfn) -- For the third year in a row, Microsoft Corp. founder Bill Gates has topped the annual Forbes 400 list of the richest Americans, with $18.5 billion in net worth.
Forbes magazine, releasing its 1996 list Monday, said in a statement that during the past decade, wealth based on physical assets has given way to riches derived from "ideas and organizing principles."
Berkshire Hathaway's Warren Buffett checked in at No. 2 on this year's list, with $15 billion in net worth.
Microsoft co-founder Paul Allen came in third ($7.5 billion), followed by financier John Kluge ($7.2 billion) and Oracle Corp. chief Larry Ellison ($5.8 billion).
Eight of those appearing on the list for the first time made their mark in software, swelling the ranks of ultra-wealthy software tycoons to 20.
At the same time, Forbes said that the number of fortunes based on heavy industry shrank top 35 from 103 a decade earlier.
Three of this year's 400 richest Americans also made their money not in factories but in television and movies.
Talk-show host Oprah Winfrey made the list with her $415 million net worth, as did director Steven Spielberg ($1 billion) and entertainment mogul George Lucas ($2 billion).
All told, 121 billionaires head this year's Forbes 400 list -- a record -- up from 94 last year and 83 in 1994.
The price of "admission" to the list also rose to a new record of $415 million, up from $340 million last year.
As a group, Forbes 400 members now command a combined net worth of $477 billion, up from $395 billion last year and far above the $92 billion recorded when the list debuted in 1982.
Other notable findings from this year's list:
- Pamela Lopker, 42, worth $425 million, is the richest self-made woman on the list, which includes a total of 60 women. Lopker started her private software company, QAD, two years after graduating from UC/Santa Barbara.
- Thirty of the Forbes 400 never went to college. Similarly, 63 members having no college degree have a higher average net worth than the list's college grads.
- Not on this year's list: Walt Disney CEO Michael Eisner ($405 million net worth) and Jeffrey Katzenberg ($400 million), the former Disney film chief who now owns 22 percent of Dreamworks SKG.
- California has the most residents on the list (81), followed by New York (50), Texas (29), Florida (19) and Pennsylvania (17).