what is the international or most important italian food?!

pizza and pasta are both dishes associated with italian cuisine.
the most important ingredient in italian cooking is however the tomato sauce.
Italians really enjoy preparing it,and for a proper italian tomato sauce to be made,it takes 4 hours sometimes.fresh tomatoes,fresh basil and various other plants,sea salt,all that cooked on a very low heat.

I would definitely say pasta. There are literally hundreds of ways to prepare it, all delicious and traditional.
I'll give you some of the important/traditional ways of preparing pasta:

- Bolognese (penne bolognese, spaghetti bolognese, lasagna bolognese, etc...)
- Tortellini alla Panna (in Northern Italy)
- Spaghetti alla Carbonara (from the west)
- Con Pesto (it means "with pesto")
- Gnocchi di Ricotta
- Penne con Fagiolini (penne with beans)
- Con salsa di pomodoro (with tomato sauce)

Pizza would be one, too, but not North American pizza, which is the "fake" kind of pizza. It would be the original, real Italian pizza. Square-shaped, no cheese, fresh, and delicious!

Me (an Italian Canadian)

Two very well known Italian foods, I suppose, are Pizza and Pasta. BUT keep in mind that pizza is only a snack food in Italy.
As for pasta, here's the lowdown on that.
Pasta is not a meal in itself: It is used in soups (Minestre & Brodi); then there is Pasta Asciutta (Italians call any drained pasta: I.E. Spaghetti, Fettuccine, Penne, Rigatoni etc.) This is served with either tomato sauce or meat sauce or alfredo sauce or other sauces. Also, and this is very important, and is also the thing North America seems not to know or not want to know: There's no such thing as a Spaghetti, or Lasagne, or other pasta dinner. Pasta is NEVER served as a main dish; it is always served by itself just before the entree. It is the entree that is the main dish. The Italians call the entree: "il secondo" or second dish.

I would think that spaghetti bolognese is the most internationally known and enjoyed.

spaghetti, pizza, lasagna