I cover real estate, writing about everything from trends in the housing markets to ultra high-end luxury property listings to quantitative lists of the best and worst cities across America. Real estate is in my blood thanks to a broker for a mom and a property developer/landlord for a dad. I have had a front row seat for the real estate market’s inflation and subsequent crash over the past decade, these days watching my dad struggle to find tenants and my mom struggle to sell underwater homes. I have been both a homeowner and a renter in the New York area and can’t decide which one I prefer. You can also catch me debating economic topics and throwing out stock picks as a regular guest on the ‘Forbes on Fox’ show on Fox News every Saturday morning. Before taking on the real estate beat, I worked as an Anchor/Reporter in Forbes Video, interviewing everyone from the Jonas Brothers to new IMF chief Christine Lagarde to eBay billionaire Pierre Omidyar. These days I shoot videos of crazy homes. I graduated from New York University in 2009 with a BA in Anthropology and prior to that I worked in the other end of media as a recording artist with Sony.

We compiled our list with the help of Altos Research, a Mountainview, Calif.-based company that tracks housing data in real time. It pulled pricing information for more than 20,000 ZIP codes across the U.S. for June 2 to Sept. 2, zeroing in on the 500 most expensive. Altos calculated the median asking price for both single-family homes and condominiums, weighting the price based on the mix of local property types.  We did not include co-ops. Altos limited the search to ZIP codes where 20 or more residences were listed for sale, including short sales and bank-owned foreclosures on the market.  To smooth out any wrinkles caused by a week’s unusual activity (like, say, an expensive home coming to market in an area where luxury properties are rare), Altos used a rolling average for the 90-day period.

Since our list is based on asking prices rather than tax assessments, it may be unfair to assume that our list is completely representative of the communities featured  — for example, there could be pockets of long-time residents in modest homes in areas that have become swankier in recent years. Rather, our list is a snapshot of each market’s current activity. “We look at listing prices because, if you were to go into one of these markets with the intention of buying a home, this is what you would see in the market,” says Michael Simonsen, chief executive of Altos Research. In some cases a ZIP may appear more than once on our list.  This happens when two or more towns share the same ZIP code.

Median home prices in the 500 ZIP codes we considered are down 2% overall from our 2010 list, which is the mildest depreciation in years. In 2010 prices were off 5% year-over year and in 2009, 7%.  Inventory levels have remained about the same since 2009, but real estate appraisers like Jonathan Miller, chief executive of New York’s  Miller Samuel , say there’s been an uptick in listings in the luxury end of major U.S. markets this year.  “It’s not that we’re seeing prices rise, it’s that we’re seeing more activity,” Miller told Forbes recently.

California dominates our list this year. The Silicon Valley property market continues to benefit from a burgeoning tech industry that’s increased housing demand. In addition to Atherton, Northern California ZIPs that rank highly include Hillsborough 94010 (No. 4); Los Altos Hills (No. 18) and Los Altos (No. 24), which share the ZIP code 94022; Woodside 94062 (No. 31); and Palo Alto 94301 (No. 36).

The celebrity-studded Los Angeles-area figures highly on our list as well. A bevy of $50 million and higher homes landed Beverly Hills 90210 in the fifth spot, Malibu 90265 12th, and the Bel Air section of Los Angeles 90077 19th.David Kramer, a Hilton & Hyland agent specializing in Beverly Hills and Bel Air properties who represented Petra Ecclestone in her purchase of the $85 million Spelling Manor, says he is seeing more $10 million and higher sales this year than he did during the heights of the market in 2005-06. The listing prices in these ZIP codes reflect that, pushing their rankings up from last year.

The tony ski towns of Colorado are also showing strength.  Despite condo prices that start as low as $105,000, Aspen’s ritziest ZIP code, 81611 (No. 20), Snowmass 81654 (No. 13) and Snowmass Village 81615 (No. 59) rank highly thanks to a bevy of estates listed for between $20 million and $40 million.  And Telluride 81435 debuts on our list at No. 28 thanks to posh pads and ranches belonging to the likes of comedian Jerry Seinfeld and formerGoldman Sachs CEO and New Jersey governor Jon Corzine.

Simonsen says that after the bubble burst, asking prices didn’t fall much in these posh Colorado ZIPs but days on the market increased, with homes languishing for an average of about a year before being sold.

A surprise on this year’s list is New York City. Manhattan ZIP codes have long featured on our annual list, but this year the wealthy Upper East Side, Upper West Side and West Village were surpassed by two trendy downtown neighborhoods: SoHo 10012 at No. 6, followed by TriBeCa 10013 at No. 7.

The SoHo and TriBeCa housing markets don’t have as much inventory as some other areas of Manhattan, says Gary Malin, president of the New York City-based realty firm Citi Habitats. “They are always highly sought after because of the wide-open loft spaces with high ceilings … and because there’s not a tremendous density of housing there and always a lot of demand, you’re able to get significant prices.” He notes it’s a very similar dynamic in the West Village 10014, which ranked 35th. The ZIP codes of Lower Manhattan, a neighborhood transformed since the destruction of the World Trade Center, debut in the top 500 this year as well thanks to new luxury condos that peddle outrageous amenities.