What do you do with a Christmas bonus?

At the grand old age of 39, I’ve been told I’m getting a performance related Christmas bonus for the very first time. This is very exiting to me, as I thought it was just something people made up. It’s not necessarily because I’m shit at my job. It’s just the first time in my career that I’ve worked somewhere that’s been in a position to offer one (yay for the private sector!). I’m being handed £3k in my pay at the end of the month, which of course will look more like £1.5k after tax, student loan, pension etc. I’m on a good salary already so this is truly bonus money.

I guess the question is, what would you do if you got given an extra £1.5k one month?