I would place the most part of the money (after taxes) at Compagnie Monegasque de Banque which would probably get me immediate lifetime tax free residency. I would be in the same place as now only on the other side of the barrier being Ms. Anonymous mega-millionaire.
I would rent property in Monte Carlo year round - nothing big. A 40 sq. meters one bedroom apt. with a balcony and a 180 degrees view on the Italian side and the sea in one of my favourite buildings - probably the Mirabeau or the Monte Carlo Sun.
I would buy a small apartment in the Ile Saint Louis, my 27years long neighborhood in Paris. I would choose a place with a view on the Seine and Notre-Dame. My places would be equipped with good kitchen and bathroom and top of the line sound equipment. A choir would sound like a choir and an orchestra would sound like an orchestra.
My top concern would be to stay anonymous. I would not live outrageously or do anything to attract attention. Whatever I get from the invested money I would spend on travelling to the world's nicest places without limitation, could be skiing in Davos, Zermatt or Klosters, staying in the best hotels and resorts around the world and dining/lunching at the world's most reputed chefs restaurants. Cruising on the Queen Mary 2 would be a possibility.
I would not buy a Ferrari. I would just hire them and race them on racing tracks. In the cities I would just take taxis.
I would get a yearly subscription to my favourite symphony, ballet company or/and opera houses. The tickets I don't use I would gift to a student. I would go to all Formula 1 races around the world every year getting paddock club for me and a friend.
I would take flying lessons. I would learn to fly not only airplanes but also helicopters. I would go to Italy to study Airt, places like Roma, Napoli, Firenze and Venezia and go places to learn the different cuisines of the world. French cuisine would come first, followed by Italian and Indian. Also I would go to fashion shows in Paris, Milano, London and New York and buy clothing from my favourite designers.
I would still be using airlines to fly places, only the top best airlines and only in F.
I would just spend the rest of my life going to all my favourite places around the world always with somewhere familiar to return to and be happy when I am not travelling.
Nothing flashy. I would keep life simple. The mega-millions would afford me a high level of comfort and sophistication I can't afford now.
[Edited 2012-03-29 08:33:22]