Well in Italy we have 4 main stereotypes we have to defend from:

1. We have no civic sense and we get recognised abroad for this

2. We don't speak english very well, or we don't even speak english at all

3. In Italy politicians are all involved in Mafia

4. We have a great cuisine

I've got to say it's not the truth!!....our cuisine is not so good! :)

A few sterotypes about my country America: there is too much gun violence and crime in America, there are too many fat Americans, because they eat too much fast food, there is too much greed and materialism in America, and there is an intolerance of foreigners who don't speak English.   Of course, these are just sterotypes that are not necessarily true. 

by the way I myself have a few stereotypes about Mexico: Tequilla, drugs, everything that forbids America allows Mexico

About Italy:Of course everyone knows Don Corleone-this image of a typical Italian ,a good  Pizza and Pasta,trains  who are late.Its funny becouse for me it is a country of the Italian Renaissance and  beautiful art <Leonardo Michelangelo, Scarlatti Visconti Antonioni  е t с 

May be , many sterotypes (or all) are created  because of the movies...

Mexico has many of them

Could be, people with strange hats (too big ones), eating "tacos" or "burritos" and lying near a "nopal".

Also (of course), the accent and some "special phrases"

"Andale Wey, vente pa' ca" haha !

If you have more, comment!