Magnier made most of his early money from bond markets, and is believed to have made a killing on the devaluation of the Mexican peso in 1994. In addition to his farmland, he has stakes in the Curragh racecourse, UK nursing home and pub chains, and a two paintings worth €70m and €25m each.
Next on the list, somewhat unsurprisingly, is the original beef baron himself, Larry Goodman. His wealth continues to grow at a rate of 10pc a year, bringing him up to €780m this year.
The 77-year-old Louth man's ABP has created a warren of offshore companies in an effort to prevent prying eyes from getting a good handle on its finances, but one company based in Luxembourg that is linked to the empire was reported to have made €280m in just over three years. He also owns big chunks of the Blackrock, Galway and Hermitage Clinics, along with many iconic properties, including Bank of Ireland's HQ, and the Revenue's base in Setanta House.
The little known Cleary family are ranked fourth on our 20 richest, having inherited close to €1bn from the late Eamon Cleary, a small farmer and dealer from the Border area, who left for New Zealand in the late 1980's to establish large dairy farms.
He subsequently made a fortune in property and telecoms, before he died aged just 52 in 2012.
While the country's other beef barons - the Allens and Achesons of Slaney, the Keatings of Kepak, the Queallys and Brownes in Dawn, Dobsons who own Dunbia, and Mallons that own Liffey Meats - are all familier faces on the rich list, there are other names and sectors that have proved to be surprisingly lucrative.
Two families amassed over €600m from animal medicines - Northern Ireland's Haughey family from their Norbrook operation, and Dublin's Tierney family who are behind the Bimeda company that makes the Bovimast, Bimectin, Endospec and a host of other well-known products.
In a similar vein, Clonmel's Louis Ronan has accumulated €74m on the back of his Enfer test for BSE, which had generated €10m in profit before the company was made unlimited a decade ago.
Fruit has also proved to be a money-spinner for the McCanns that own Fyffes and Total produce, and the Keelings. Between them they are sitting on over €200m.
Another niche product that has made a fortune for one man is the mushroom. Former teacher, Ronnie Wilson controls both the Irish and British mushroom market from his base in Monaghan, and is reputed to be the largest producer in Europe.
He has bought Dutch and Canadian based companies that has given him a foothold in both European and North American markets, and now employs over 3,500 people worldwide.
It would be a national disgrace if Ireland didn't have at least one spud multi-millionaire, and two men north and south of the Border has done very nicely out of the humble tuber.
Raymond Hutchison owns Manderley Food group, which owns the Tayto and Golden Wonder brands in Northern Ireland.
Further south in Meath, Ray Coyle has been the Tayto maestro, netting €45m when he sold out to a German company last year. The 64-year-old still owns the huge leisure facility, Tayto Park.
Finally, Ireland's farm machinery entrepreneurs have also done nicely for themselves, not least the McHales from Ballinrobe. Their balers have made some serious hay over the years, with the brothers now sitting on €108m of assets.
In recent years, the brothers have teamed up with fellow westerners, the Comer brothers from Galway, to buy prime Dublin 4 sites, including Ireland's most expensive site during the boom - the €171m Ballsbridge site that was subsequently picked up by the western consortium for just €22m.