Pick the order that is most exciting for you! They key to the process is to keep at it and you should use every trick you can find to make sure you stick with it. Three years can feel like a very long time.
The debt snowball, while not the mathematically maximized order, is set up to give you milestones along the way and give them to you early: the first debt you pay off is the smallest so you get that sense of accomplishment as soon as possible. And when you roll that old payment into the next, you see the larger debt disappearing faster (the snowball effect!).
Other folks get that satisfaction from maximizing their paydowns and focusing on the highest interest balance first, no matter how small of an advantage there is. If that is what keeps you working at it, do it.
Personally, my second mortgage is the one that bothers me the most, even though its not the smallest or the one with the highest interest rate. Its the one that gets under my skin and irritates me. Paying extra money towards that one just makes me feel good and I want to keep paying more!
You should still do the math to know how much more you are paying to make your choice; knowing that information may change your answer. If I had credit card debt at >22%, that would most certainly be where all my extra cash would go since I can't stand interest rates that high. My point is that you should pick what works for you given all the facts including understanding what motivates you and keeps you working towards your goal.
Get started and stick with it!