You first need to know your avatar. Who is your avatar?  And then, what is it they search for. Then, only after that, do you do your keyword research. 

You do your keyword research to discover an EMD you can use that will fly under the radar of zippo. 

That will be your domain name for your website. 

Then you get a vanity style or tag line style domain name to point to your website. The vanity one is what you put on your cards, etc so that your peeps don't end up on your competitor's site by missing one letter. 

We use NestorGasset.com on some of our marketing and on others we use FloridaIPI.com  - Those of course are of no use for SEO. So the main name of our websites are keywords we want to rank for. 

The exception is if you own the company, so for us, we also have to have  real domain name ( not forwarded) of our company name. But if you are not the broker owner, stick with the SEO part of the equation. Katerina

Go with Union County, or you may want to buy all 6 domains and point them all toward your webpage.

Similar approach here, we went with WarrenCountyOhioRealEstate.com

If you could get UnionCountyNJHomesForSale.com you'd have a keyword rich URL which is a good start towards getting found.

Wayne and Jean Marie Zuhl - I'd not change this domain name if I've been using it for years! Stick to it! SEO may come from blogging with keywords. I know website address is important - however, use some tags etc.

(I am NO expert at that - this is just my two cents.)

Who is your target market? Is there a commonality to buyers of homes in all these locations? What do they enter to find homes for sale? THAT would be your domain name.

I cannot add to Nestor & Katerina Gasset's words of wisdom.

I'd pick a geographic location..... 

I have: todarosellsfranklinma.com

I'd get the city + homes.com as well as the county+homes, like Susan Emo said.  I'd also look into doing those with "real estate" instead of homes, depending on your budget.

Primarily, I'd start with some research and see what sites are out there already (hint: you'll probably see a couple sites with Realtor in the name).  I'd plan accordingly based on what is out there and my budget. 

I had looked into getting a whole bunch of these domain names myself and pointing them to my primary site.  I'd also reach out to Nestor & Katerina Gasset and pick their brains on if there is any negative SEO impact for having domain names that are just forwarders to your primary site.

I wouldn't give up your current site, especially since I'm sure you have some SEO built up for that site and some infrastructure around it.

Is there a way to classify the area?  Like here we have lower Westchester county, or Northern westchester, or River towns.  Just a thought.  Also, if there a specific niche or is it just geography.

We can prob. brainstorm on Monday.

Also, go to google keyword planner (free) and you can see about some of the searches volumes on there.  Sometimes that helps, sometimes not much data.

I have also seen domain names like "adjective homes in XYZ"

where adjective could be awesome, luxury, exclusive, amazing, whatever.  It may make it easier for people to remember...you want keyword rich and catchy, if possible.  (more important to be keyword rich)

Wayne and Jean,

Take time to study this.  Look at your marketplace talk to them not us.  Walk the streets were you sell, go to the parks.  Go to the downtown area, walk around the stores...see the homes you sell in a new light...become the area, talk to each other about your business who you are what you stand for, etc.  That is what why we do for our clients when we travel...Do it right!  None of us work there.  I know you can do it.  A

I'd go with UnionCountyHomes.com

Name those towns, that's your target.

I would promote the name with real estate and not just the location, make it memorable-like marketing suggests. SEO will make you pop up and you are not tied to an area name

Zrealestate.com

Zmarksthespot.com

realtyZ.com

ZZRealty.com

ZZsellshomes.com

I'm bad at coming up with suggestions, although I've found that wine helps when I doing it for myself.  Oh, and pay attention to what Katerina suggests.  She is good at this without wine!

Something like UnionCountyHomes.com or UnionCountyProperties.com may get some looks. Capture that url and route over to your existing site.

I think you should use the geography in some way, coupled with "real estate" or "Homes." And there are some good tips here to think about before making your decision. And some great URLs might alraady be taken

Incorporate Union County NJ somewhere in the name.  

unioncountynjrealestate.com would be my first choice or  any of the cities you can buy and then forward them to the "county" one.  I own several.  lake-sinclair.com is what I use, but properiesforsaleatlakesinclair.com points to it, lakesinclairrealestateagentreviews.com points to it.  those additional urls that fairly inexpensive being forwarded to it gets me additional traffic.

Area-agent.com

How about New Jersey home compass?

I like what Liz and Bill Spear said.  You can drill down from there, within the site, for SEO.   Have you thought about buying domains for all those towns and linking them together?

You should go to a site that shows you whether various domains are available and type in potential ideas.

Sounds like you will be spending some time researching name availability. Have fun!

Not knowing anything about your geographic ... I feel that the County may be too large.  I'd go with the largest city with the most opportunity. For example LindenHomes.com or LindenHomesForSale.com

Union County-NJ top realtor

Union County-NJ top agent

Union County-NJ homes

etc

UnionCountyRealtyGroup.com

Your your domain does not need to be keyword rich, particularly when County is not appropriate and you cannot cover all areas in the domain name.

Your current site is your brand name, you should consider sticking with it. You will get best SEO benefit by creating unique pages for each location. On each of these pages you can mention the smaller local names that people search for. You can largely duplicate some information on each page, but also include very localised information.

I don't see an About page on your site, so you have not sold me on why I should come to you. You can also sell your USP and expertise on each local page.

If you do want a new domain knowem.com is a quick way to check .com, .net, plus Twitter, Facebook and other social sites - all in one search. But occasionally some results are not 100%, so if you find one you really like, double check before going too far.

County name in it.

Use your name.

Nestor & Katerina Gasset nailed this one!

Katerina is the expert.