We have gotten the big Pink donut both trips now. The photo opp is awesome! plus, it's great for splitting.
I do like frozen butterbeer
A MUST-DO is cheesecake from the boulangerie - its just as good as the Cheesecake Factory IMO and cheaper - $4.89 a slice.
My son loves lemon slushes.
I will say - there aren't a lot of snacks/meals in Universal that are must-dos for us. One evening I was looking for somewhere to eat in the parks and couldn't come up with one place I particularly wanted to eat in (our 3rd day in so we had already covered many of our must-dos).
I tried Cowfish this trip. I honestly wasn't expecting much but decided to try it based on so many recommendations here. LOVED it! Incredibly yummy sushi - maybe some of the best I have had (admittedly, I typically only eat sushi at a few of my favorite places). We were going to go to Mythos and i ended up nixing that in favor of a second trip to Cowfish. YUM!