When someone says something has smug appeal, they mean it has a set of qualities that make it attractive to smug people (i.e. people who like to take excessive pride in themselves, usually because they are rich or upper-class)

One of the douches from Charlottesville, VA. Usually a stuck up person you has decided their shit doesn't stink. Walks around with a stick up their ass complaining nothing.

Smug's underground is
a place on the internet where people who are too smart to be popular, but not smart enough to get away with it, gather. The Smug Underground is a secret community of free-thinkers and thinkers that doesn't take themselves seriously. We're here for the ideas, we don't care about your status or your title. Come join us! You'll fit right in.
The Smug Underground was created by an anonymous group of writers from all over the world, united by their common interest in getting rid of freedom of thought, speech, expression, action, belief, opinion, lifestyle, religion, race, gender, sexuality, nationality, language, culture, ideology, origin, wealth, power, or anything else. They want you to believe what they say, think what they say, do as they say, be like them, dress like them, live like them, love like them, hate like them, have no will of your own, obey every order given to you without question, accept everything at face value, and most importantly: never ever dare disagree with any member of the Smug Underground.

A person or couple previously interesting and good conversationalists who now that they have children talk about nothing other than everything their children do no matter how mundane and are utterly oblivious to the fact that they now bore the shit out of everyone.

Someone who is completely self centered, selfish and conceited. A person that will destroy the world to get their way and sell out anyone in the process.

when someone apprciates their own relationship to the point that it makes everyone around them want to throw up

You think you all that cool are you?