I'd probably go comatose from shock, but if I didn't...
Pay off my dad's ranch as well as my stepmother. Also get his airplane fixed and his runway paved.
Pay off my mom's ranch.
Pay off my little's brother's college expenses.
Give some money to my grandparents so my grandpa could finally retire after being a cattleman for 60 years.
Buy my older sister a house a new car (seriously her car is...something...no A/C in balmy Austin, TX), and a studio for her to create more art comfortably
Buy my older brother a house (or camper or whatever) a motorcycle, and a garage for him to work on it.
I'd also give money to a really good friend from high school whose mother just died.
For me...
Buy a house.
Buy a bitchin computer
Buy all the camera gear regardless of need.
Travel lots.
And give $500 tips to waiters/waitresses at restaurants.
To be honest, I don't really need or want much - at least in relation to how much money I would have - but it would be nice to have the means to help out others.