For me, it's $1,150,000.
If I won the lottery (not likely, since I, uh, don't play it), I'd take that amount and give the rest away to my family and friends. If it was a ridiculous amount (like, more than $10 milllion) I'd probably give a million each to my parents, in-laws, SIL, brother, and best family friends, then spend some real effort and research and time investing the rest into charities (like the provision of clean water to communities, promotion of local agriculture to exploited nations, etc.).
Why $1.15 million? $100,000 would wipe out our debt including mortgage. $50,000 would be nice for a few fun things like maybe update our bathroom a little, a little vacation, maybe a $500 clothing spree, just a few things like that. The remaining $1 million would be our nest egg, we'd live on 5% a year which would be plenty for us and probably allow for inflation too. We live on 40k right now with all our debt, so 50k and no debt would be living high for us. And that's all we'd need. After that I would just give it all away.