What I'd do:
-Remain anonymous from the start.
-Tell no one, except closest family.
-Agree to the monthly installment option for a couple of years.
-Live a frugal lifestyle, almost equivalent to what is current.
-Invest the monthly installments each month.
-Blend in.
-Treat myself and family to a vacation together each year that is still economical.
-Live healthily. Cut out all the junk.
-Read books.
-Help the poor and needy by giving out food parcels. Donate to charity organisations (for tax deductions).

I'd invest it all.

That's what many lottery winners neglect ever doing: investing it from day one.
They don't think of it as a means of investing into their futures and for those of their family members.
They take it automatically as a fix to all of their problems. Spending it on lavish lifestyles. Picking up luxury debt. Not knowing what harm it is actually doing to them in the long term.
..Then they hit rock bottom.
Living with their parents. Relying on the dole. Etc.

''A fool and his money are soon parted.'' - comes to mind.

Spend it all

I'd remain single
Women are bloody expensive
Never get married as then you have a legal obligation to split it and all that if divorced or 'murdered' by a hitman or something

Also, many people from your past will claim to be your best friend and all.. and as well as outsiders wanting to sponge off you.

Remain anonymous.
Live as frugally as possible.
Keep your head held up high!

Buy some hope that my dad finally comes back from nipping to the shop for some cigs

Son.... is that you?

Don't be silly, you're infertile.

I kept you in my belly for 9 months, breastfed you, taught you how to walk and talk, changed your diapers, gave you tips on how to date moomins successfully. And this is how you repay me in the end? Calling me infertile?

After I'd picked myself up off the floor, I'd .... hold on I need to think this thru... how many millions are we talking? I dont want loads, enough to see my kids n grand kids financially sorted for life, ohhh dunno if my kids would want to give up work tho

Same as what I do now but on a bigger scale I suppose.

Dream house would be getting bought and I'd luxuriously fu*k off round the world with my crew

I... I don't think you know how time works or quite a few other things, apparently. I think we need 'The Talk'

i'd live undercover and keep the money as safety-net only.

Wouldn't cost much to do what I want, and it'd be easy to keep secret. Would then be fun seeing who I could help out, and getting them on board with the ongoing operation...

Nobody would know if I won it. However I would really enjoy helping people out but do so anonymously.

I'd be dancing with a different corner flag each night

Become an evil mastermind of some sort.. why not? All you need is a swivel chair and a cat. Got the chair already.

Move very far away from everything....build an off the grid eco home
Set up a trust fund for family
Then help out various good causes every morning before I feed the chickens ....
Chill

And by ''everything,'' you mean ogdenz. Blink twice for yes, we can send help.