I am boring and generally make turkey and cheese melts in mine. sweatdrop Or quesadillas since my "panini press" is actually a Cusinart griddler with interchangeable plates. xd
However, I am aware of some more creative combinations that sound good. I just can't be bothered being terribly creative about my food lately (college classes are a pain sometimes, lol).
You could try...
Thinly sliced apples with brie and cranberries
Chicken, peppers, and onions with a "Mexican blend" or pepper jack cheese
Thinly sliced vegetables with cheese (type of cheese might depend on your veggies and your preference)
Basically anything you like in a sandwich works well in a panini, but sometimes you have to play around with the cheeses to find one that melts well and still goes with your other fillings. Experiment! biggrin
I had to google what a panini is... in this country, the vast majority of people would just call them a toasted sandwich. xd
There was a bakery I used to go to where I would always have the same toasted sandwich panini - turkey, cream cheese, alfalfa sprouts and cranberry sauce. On the one occasion I went there and they had run out of cranberry sauce, I had avocado, which was equally divine.