Americans aren't portrayed as fat stupid lazy in Hong Kong. The "lazy" stereotype somehow doesn't exist here.
I think the only ones who are portrayed as lazy are the Greeks. (And the media does shape them to hate Greeks)
The Bad bits:
But Americans are portrayed heavily by the media to be bossy and think that every country's business is their business. This is due to the fact that whenever some countries are in war, USA seems to be involved. And the fact that Americans tend to sign petitions on just nearly anything. (especially animal rights) This includes butting their heads in for "feminist rights" for women wearing hijab.
Main stream Hong Kongers believe that whenever 2 or more countries fight, it's their own business, and it's none of anyone else's business.
Main stream Hong Kongers believe what Muslim women wear have nothing to do with people who aren't Muslims.
They are perceived to be ethnocentric -- they think it's ok to eat pork/ beef, but invent a moral difference on dog meat or other meats that Americans somehow don't eat, and believe that they are more moral than Asians.
Despite the fact that dog meat is illegal in Hong Kong, and that most Hongkongers don't like the idea of eating dog meat, majority feels that Americans should not voice out for the dogs-- because American people are not dogs, it doesn't directly harm them. It's called having too much time concerning stuff that doesn't directly matter to you.
This is also worsened by the fact that a lot of American exchange students come to Hong Kong without thorough research on Hong Kong's culture. They come to Hong Kong and demand everything to be done in the American way.
They are perceived to be rude -- many don't say "please", "thanks", after ordering something, whilst Europeans would have said these words. Use of informal English when speaking. (Usage of slangs are perceived as lower class behaviour in Hong Kong)
They are perceived to have bad manners -- not dressing formally enough for posh areas that used to be white man's area. Not eating according to European's standards in posh places (also used to be white people's restricted areas).
(These areas still exist in Hong Kong. Apparently all current posh areas in Hong Kong used to be white people only areas.)
HOWEVER
The good bits:
They are perceived to be good Christians.
They are perceived to be helpful-- they would save a person's life even when they don't actually know him/ her. Some may even rescue their enemies. They are perceived to be willing to help a neighbor.
They are perceived to be very nice to animals. We often get news on how Americans help dogs or other wild life/ rescue them, etc. We also get news on how American traffic would stop if some animals are crossing. (Which doesn't happen here-- the trains will not stop and always kill the stray dogs or whatever animals they may be.)
Americans are perceived to be creative. Aside of most inventors we know are Americans, Disney is also American. Disney is big here. For small children, Disney can be bigger than Japanese anime.
Americans are perceived to be generous-- because of tipping!!
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Regarding to American systems.
American education is perceived to be very good. (Seriously!!) It is perceived to be very advanced with cutting edge technology. Parents spend millions of dollars to send their kids to American schools. They think so because most inventors of science/ tech stuff are from America.
America is perceived to have cutting edge technology. When people think of America, they think of science and technology.
They think that every American is good at science, despite not good at maths. Almost all scientists that an average Hongkonger knows of is an American.
They think that American cops are very nice people. We often get news stories about how a group of cops helped autistic boys to celebrate their birthdays, something like that.
