This has varied over the years depending on the criteria used(population for one) .  Besides the cocktail party conversations it can inspire, I don't see much impact on people's lives. Just my opinion. 

With one-half of the tech billionaires in the U.S. living in Silicon Valley, the San Francisco Bay Area is certainly up there.

La Jolla, CA in San Diego County

most of the towns in my area have a population of comparable income range....

That would be zip code 28207, followed by zip codes 28210, 28211 in Charlotte and then Cornelius (all in NC).

I saw a question on this yesterday & I'm not sure why it would matter. Those numbers are for entire U.S.

Kenilworth, or 60043, came in at No. 8 with an average income of $861,000.

Glencoe, or 60022, came in at No. 19 with an average income of $633,000. 

Orlando has low income to the very wealthy..

Highland Park, Dallas County, TX

I serve a very wide area and the numbers mean very little. Why do you ask?

I am with Michael Jacobs and John Juarez - Silicon Valley, CA

Rancho Santa Fe and La Jolla, San Diego County, CA

What I can tell is that Santa Barbara County has 16 billionaires that live there or have second homes.  We aso have many Ultra High Net Worth which is below a billion to 100 milling, and many High Net worth wich begins at 30 million up to a 100 million..They can be found in different neighborhoods throughout the county, and in the different cities and areas of Santa Barbara. A

Probably Jupiter Island in Hobe Sound, FL.

The richest town in Maryland is Travilah, population 11,989. Located in Montgomery County, it has a median household income of $208,421, far above the state median household income $73,971 (the highest in the U.S.).

I'll go with Lyn Sims on this one for Illinois although Winnetka should be right up there!

Here in NH it is Londonderry NH, a town just South of Manchester NH. The median income is  $85,993 

Edmond, Oklahoma is in Oklahoma County.

Scottsdale

Good question, I have not been inspired to research this before.

Here in Florida we have MANY, from the East Coast, West Coast, Central and North Coast. In my area, we have Fisher Island, Miami Beach, Indian Creek Island, Golden Beach.

I've done business on Mercer Island WA, 98040 home of Paul Allen, the Nordstrom Family and a few others. I've shown homes in Medina, 98039, home of Bill Gates & Jeff Bezos, but I don't recall completing any sales there. 
I try to work as much as possible in Sammamish where I live with a median home value of $900+. 

There are many

That is really easy. Bend, Deschutes County, Oregon

Valencia, California. Los Angeles County.  $124,362.53

No idea off hand.  Too many different cities and sub sections.

   Northeast Tallahassee.   Particularly Rosehill, Golden Eagle, Moore Pond.

North Scottsdale.  Median income is $101,000. 

No idea. We have condos from 85K to 38M

I serve Clarksville, Tennessee which is Montgomery County. The part of town that has the highest income is Sango.

Probably Castle Pines in Douglas County, Colo.

Cherry Hills and Castle Pines

It is close to $250K, Ritu Desai 

Madison, Morgan, Georgia

In my area there are 3 or 4 communities that are very close in values