That's a tough question because it all depends of what makes you happy. You can take a day trip with the family, go by some needed clothes, put towards the house, buy your wife a great present and, of course, spend on what makes you happy.
This is Sideshow Collectors Forum so obviously you will find people saying "Go get a PF, Dio or Maquette that you wanted for a long time but didn't have the money.
It is a hard questions but i can only speak for myself. Because I have Robocop, Aragorn and Leonidas PFs coming next week,
I will spend going out with the family somewhere.
If the money was to spend on myself only, then I will buy something from Sideshow website...