I go to school in the birthplace of Sonic - where there are probably a good 3x as many Sonic's as Starbucks'. My favorite things are caramel java chillers, butterfinger-oreo blasts (some places will combine them without making you pay more!), and chicken club and grilled chicken sandwiches. Oh, and I always get the strawberry limeade with no ice (so you get more beverage).
I'm from CA, and the nearest Sonic there is like 5 hrs from my house, so I love being at school for the wealth of them (there's one basically right next to the back of campus). Even when I lived in VA for a summer, I had to make a special trip of them, because there was only 1 within about 15 mins of me.
I do wish it was cheaper though. But I suppose the expense saves me from being super unhealthy.