Buy a bigger appartment, a car, a girlfriend who loves me for my money and a horse!
Then I'd reward myself with a gallon of milk and an entire pineapple!
In all seriousness though, a better place to live, a little car and an appartment for my dad and one for my sis.
And I've met so many people far worse of than me through my job and daily life, met quite a few kids and families that I'd love to help out in any way possible. Give them some money or send them on vacation for a few weeks or whatever. Just give them some peace and quiet, a break from their everyday lives.
Would warm my heart