I can honestly say in my heart of hearts, this is what I would do and what I would drive.
My everyday driver would be a bullet proof (B7 or better rated) Mercedes G65 with Renntech engine upgrades. Electric door handles, oil slicks, tack drops, etc, the full security package. From my research it would cost nearly a million dollars to purchase this vehicle and then add the level of security upgrades I want to it. Car is about $250k, engine plus security upgrades are the rest.
I would then purchase as many examples as I possible can of my favorite car of all time, the Ferrari 288 GTO. There are 272 examples in the world, I would literally buy as many as I could for fair prices. Dozens if possible.
I would also have:
Mercedes G-Class Cabrio Final Edition
Mercedes S65
Mecedes CL65
Mercedes SL65 (all newer mercedes having Renntech or Brabus upgrades)
Mercedes SLS
Mercedes E500 Limited (rare car most people don't know about)
Bentley Brooklands
Rolls-Royce Wraith Coupe
Numerous Pagani Zondas (the different special editions)
Pagani Huayra
Restored Hummer H1
Ferrari 458 Spyder
Ferrari F40
Ferrari F40 LM
Ferrari F50
Ferrari Enzo
No LaFerrari though, I think it's ugly.
The Ferrari 308 used in Magnum PI (actual show car, I heard they had 3 or 4 cars throughout the show).
Numerous historic Ferraris, such as California Spyder LWB, 250 GT Coupe, 250 GTE, 250 LM, etc.
I would also commission Pininfarina to produce custom Ferraris.
Bugatti Veyons, several models including Super Sport, Grand Sport, etc
2015 Nissan GTR
A few 1990s Nissan Skyline GTRs
That's all I can think of right now. I would probably have a few more unique and collectable cars.
I would keep my collection to under 100 cars. Anything more would be hard to track and really enjoy.