Donate 1/2 of the proceeds to charity, disburse 1/4 to appease the immediate family members and with the remaining 250,000...go rent-free and purchase a house for under 85,000 (you can get some very nice houses out here for under 100,000), and pay all of the closing costs (round up to 90,000). Furnishings and property adjustments (50,000). Set aside a lump sum to pay property tax and cover unexpected maintenance costs for the next several years in savings (25,000 for 5 years at maximum). Trade-in my current vehicle for a fuel-friendly SUV, upgrade insurance premium, etc (~55,000)
I think you get the general idea. If anybody here ends up winning the sweepstakes in the future...please be responsible with your money. Real property is a great investment in the future with more weight in capital than whatever market investment options are available through your bank.
(Some people might be thinking, "why donate the money to charity?" It might seem a little greedy but charitable donations are a tax deductible expense (at least here in the United States). A charitable donation of 500,000 is sure to put you on someone's map...not to mention, once again, the expense is tax deductible.