This is a hard question. I always like to save the best for last, so I'd take into account what everyone in the family's expectations were, and decide from there. Dh is "disneyed out" and ds is into Spiderman, so we would do IOA last, but if it was just sappy sentimental me, I'd have to do MK last.
You might also take into account energy levels. Our son is 5, so we don't do the roller coasters which makes Universal and IOA much more relaxed and easy compared to Disney, plus I think the parks are smaller and more compact. We do just about everything at Disney, especially MK, so those days are much longer and tiring, so I would probably do those first.
Also, if you're driving down, you might want to go to Universal in the middle of your trip so you don't feel like you're in the car a lot.
Between IOA and Universal, I'd definitely do IOA last. The theming is better and I just thought it was more fun and exciting.
I love POFQ! I wouldn't have a problem staying there and driving to Univ either, especially at that time of the year when I don't think it's necessary to have FOTL. Getting to and parking at Univ is a breeze too.
Hope this helps a little. Have fun planning\!