Depending on how much. $100,000-$500,000 - buy a house for my mom and I (nothing big, 2 bedrooms, 2 baths, single floor plan, a nice fenced in yard for my dog, in a nice quiet nature scenic location, oh and after surgery I'd definitely want a pool to swim in), a car (nothing extraordinary, so not anything expensive, so long as it runs), and surgery (sex reassignment surgery and shaving my adam's apple down a tad), that's about it, the rest of the left over money would be savings.
If say $1,000,000, all of the above plus my mom would want to make sure her grandchildren were taken care of, that they'd have a ton of money put aside for education after high school, even her other two children even after the terrible things they'd done to us, such as throwing us out on the street, my mom said that she would not leave them out, because still regardless of what they'd done they are family, even if they don't act much like it.
$10,000,000 or more, all the above, and well I like my life to be relatively simple with simple things, my mom and I would be able to live comfortably, not have to worry anymore about how we are going to make it this week or the next, that kind of money would last us a life time, especially if saved and earning interest off of it. My mom and I have had a conversation about this a few times recently, I told her I'd help out other transsexuals that were very lacking on money, really wanted surgery, MtF as well as FtM, obviously I'd have to get to know those individuals that I chose to help out, I got certain standards of how I'd chose, would be based off of my own morals though not as strict, can't expect everyone to live as I do, basically I wouldn't want to waste money on someone that even after surgery still continues to be unhappy with self, or self-destructive when it could've gone to someone else that would've appreciated it to the fullest without second guessing. Hey $1,000,000 would buy pay for a lot of surgeries. Why would I do this, ugh, I don't need that much money (I've never been greedy, heck I don't even pick up change off of the street), and know what its like to want something and feeling that you may never attain it.