How to best use "extra funds" to pay down debt

I have debt that is difficult for me to manage month to month, but I think I finally have it under control where I can play minimum payments.

Recently, I had an unfortunate, minor incident which gave me money via the insurance. So instead of using the money to replace the materialistic things that were taken, I would like to put it toward my debts.

What is the best way to use this money? I know there are systems out there, like snowballing, etc. But I am taking about a one time bulk payment that will help me get a jumpstart on debt relief.

I have multiple credit cards, some with high interest rates and high balances. Others are with medium sized balances and fixed payments (because they were cards that I opened when I was trying to fix my credit).

What is the best way to go about this? What card should I pay off? Or just make a big payment on one card?

For example, I have a CC that is fixed at $15 per month but the balance is low enough that I can pay it off in full. Another card I have has a high balance, I can't pay it off in full and making a large payment might make my monthly payments go down about $20 per month.

Help?