I would say what we europeans view as the US national dish, any one of:
- hot dog and fries with cheese. and sauerkraut. REAL 1950s style dog in a REAL bun with French's american mustard, mmmmm.
- surf 'n' turf.... that's a US thing, y'know
- Philly cheese steak
- club sandwich
(begins to salivate, hmm, cheese steak, grat low carb meal.....)
will I go on...... y'know, despite the mickey D's everywhere and taco bell, you USers shure have come up with some tasty dishes.
BTW, chop suey is from San Francisco.