A lot has been written on the forum about having quality domains if you want to be successful. Everyone seems to have their own idea what a quality domain means.
What do you consider the most important factors that make a domain a "quality domain"?
If you own quality domains, you know it
You normally also get unsolicited offers and inquiries from time to time
There are many parameters but generally speaking desirable domains are those that are memorable (advertising-grade), brandable and somewhat unique. And needless to say, in a credible extension. A name that you wouldn't put on a business card doesn't qualify as a quality domain.
IMO A true quality domain is domain that is going to sell without a doubt if the price is right, whether it be $50 or $5000, it's liquid in one price range or another.