Foods I would miss (and which are available/in season at this time of year) if I moved to the US:
Speckwürfeli. Nothing special, they are just bacon bits - but I appreciate the small diced form factor instead of slices that I then have to cut up or crumble myself.
Burrata. It's a little pouch of mozzarella (and you ain't never had mozzarella like this either) with a ridiculously delicious oozy mozzarella-and-cream filling.
(Yes, I know it's not Swiss, it's Italian, yada yada. Don't care. The OP can at least get it in Zürich and chances are he won't be able to in the US.)
Saucisson fribourgeois or saucisson vaudois (fribourgeois is smokier, vaudois easier to find in supermarkets). The typical preparation is just simmered (don't boil it) for about an hour but treat yourself: do that, and then stick it in a hot oven for a few minutes before serving to crisp up the skin. No Swiss I know eats it this way... and none of them know what they're missing. Seriously I could eat this, with mashed potatoes and leeks, about three nights a week this time of year if my waistline would permit it.
Blut- und Leberwurst . Blood sausage and liver sausage. Simmer one of each in hot water (again, don't boil, they will burst) and eat with sauerkraut and mashed potatoes. You don't eat the casings of these so no point crisping them up in the oven á la recipe above.
Game (venison, wild boar, etc.) with all the trimmings. We're right in the middle of the season for that now, so go find a restaurant that's known for it and eat Hirschpfeffer (or Rehpfeffer , or anything else on the menu ending in -pfeffer ) with all the trimmings. Did I mention the trimmings?
Heisse Marroni . Hot roasted chestnuts sold by street vendors in a special two-sided paper bag. One side is for the nuts, the other side for the shells so you don't have to litter. Very Swiss and also very tasty.
Rösti. Similar to hash browns, a bit butterier and crustier. There are packet mixes in the supermarket but just don't. Find a restaurant where they do it really well and have it there.
ETA: Ovomaltine crunchy cream . Forget Nutella. Eat this.
Foods I wouldn't personally miss, but can imagine you might someday be asked about :
Rivella. Soft drink made from whey. Something of an acquired taste.
Cervelat. A sort of overstuffed hot dog, nationally beloved for reasons unfathomable to me. I think it must be a childhood nostalgia thing. But yes, if you are out on a hike and you stop for lunch and there is a fire, grill a cervelat over that fire and eat it. It's not unpalatable and then you can say you've done it.