NEW YORK (Reuters) - The priciest neighborhood in the United States is Alpine, New Jersey, home of hip hop stars such as Sean "Diddy" Combs, according to Forbes.com, which on Friday released a list of the most expensive zip codes.

Around 20 miles from Manhattan, Alpine (zip code 07620) is a small community of sprawling mansions with a median asking price of $4.14 million, Forbes said on its web site, adding that stars drawn to the neighborhood include musician Stevie Wonder and comedian Chris Rock.

Atherton in California (zip code 94027) was the second most expensive, with a median asking price for homes of $3.85 million, followed by New York City's West Village (zip code 10014) with a $3.5 million median asking price.

Even such pricey neighborhoods have not been immune to the economic downturn that has hammered real estate prices. Forbes said prices fell 23 percent in the past year in Alpine and Atherton, and by 24 percent in the West Village.

It said the average price of homes in the 100 most expensive zip codes on its list was down 7 percent.

Among the few neighborhoods to buck the trend was New York City's Upper West Side (10023), where prices edged up 4 percent, and fourth placed Duarte, California (91008), where prices rose 18 percent in the past year.

Other prestigious neighborhoods that made the list include Beverly Hills (90210) in fifth place and Aspen, Colorado (81611), in 20th place. All of the top 10 zip codes were in New York, New Jersey or California.

(Editing by Vicki Allen)