After reading the article & all the comments to date, here is my own two pence.
This article is worse than useless. let's go through the 5 listed, shall we?
1) 
The Home Devaluers
Who they are: They're friendly enough. They just never seem to mow their lawn more than once or twice a year, and they have a 1978 Buick rusting in their front yard. Granted, if they're bad enough, you may have noticed this before moving in, but even a stopped clock is right twice a day: They may have looked presentable when you gave them the once-over.
How to handle them: Communicate, communicate, communicate, suggests Jodi R. R. Smith, author and etiquette consultant in Marblehead, Mass.
She knew a group of neighbors who were upset that a house on their block wasn't taking care of the lawn. The neighbors assigned a delegate to knock on the door to discuss the yard, and when the owner came out of the house and the problem was explained, she broke into tears. It had turned out that she was in the midst of a divorce and an aggressive chemo treatment. The neighbors then organized a rotating schedule of lawn care for the ill neighbor.
"Things are not always what they seem," says Smith.
Okay...actually this was the only bit of the article worth quoting. The sad truth is that many of those who complain about unkempt places lack compassion for their neighbors. Then again, sometimes the story is more complicated. The property may be tied up in litigation or ignored by the company that foreclosed.
The real people behind this label, when it is a regular person -
The Devaluers.... range from people persecuted by Mr & Madame Urban Neatfreak - who sometimes try to rule the countryside with the HOA standards familiar to them from richer suburbs...to people with serious problems (health, finances etc) maintaining what they have, to folks used to stretching to get by with old cars/parts/appliance repairs in a neighborhood that doesn't do that sort of thing (Maybe it used to?), to serious jerks actively trying to ruining their neighborhood with junk...as a choice...like the neighbor who piles up manure in a junky tractor shed that she knows very well faces your front yard...but keeps the yard she has facing the street well landscaped...
or maybe they are too afraid of their neighbors to go outside
2) The Dangerous Neighbor...may be that way in self-defense...there are too many out there who ramp up all over anyone who doesn't look like they can fight back. Not everyone can fight back with lawyers...and a quick glance at the comments will tell you how often the local governments & landlords fail to support threatened residents, especially unpopular, unconnected ones. This is the 'dangerous neighbor' who may actually be decent. You may not have identified the real hazard.
& sometimes it is the Neighbor who is the psycho...sadly if they are wealthy, well-connected, or very persuasive types who know how to play 'the appearances' game...they may threaten you day & night and still give YOU the reputation they richly deserve when you react!
(In fact, I have seen this double victimization in action in social circles. Skilled liars love it. They will say so and so hates them and is calling them names THEN openly provoke the person and go See! See!" if the individual responds at all...or even lie and say they did if they won't...It's sick..but it happens.)
If you are really sure that’s Hannibal Lecter next door…don’t bug the man, especially at dinner time. The best defense is not to be offensive unless you are part of the LEGAL swat team that’s about to shoot him. Increase your own defenses every way possible - if you cannot move, and keep close track of each other in the household…which is the same advice those beset by misled vigilantes have to take.
Some people got that their ‘scary’ reputation from bad-tempered hags that want to see them dead…and are hoping you will be trigger-happy enough to do it for them if they tell you enough tall tales.
3) Some
Rich Neighbors are quite decent folks...and I have NEVER heard of such a neighbor called bad... except-rarely- by a foolish, envious soul deliberately causing trouble with slanderous gossip. Usually the person knew them before they were a success.
But that's not nearly as common as a jealous neighbor mistreating someone they think is just a little bit better off. The truly rich are exactly the ones who can hire a detective to prove someone is slandering them...and then pay the lawyers to make them sorry for it.
One of the worst things that commonly
does happen in rich neighborhoods is a difference of cultures running headlong into differing expectations. One fellow in a millionaires' planned community ran into trouble for growing the loveliest flower & vegetable gardens you ever saw, because that’s what well off-people did in the area of Eastern Europe where he had come from as a child. His front lawn remained a lawn, his maintenance was perfect, but his neighbors were outraged that his idea of the allowed 'garden plot in the backyard' was enough to supply his McMansion household for a year with rosewater, herbs & veggies. Seriously! He was generous with his goodies too, but most of his neighbors hated him for being productively frugal. (Personally, I thought it looked great!)
Some rich neighbors ARE bad..and - again - there are some lovely examples earlier in the comments. They bully with their toys, their connections, their legal loopholes, and the simple fact that other poorer folks in the neighborhood want to be on their good side and so find it easier to find excuses for the rich guys...and excuses to disbelieve a poorer, less attractive victim. The only thing you can do is document the overt abuses as best you can and use what clout YOU have as a citizen etc.
One abuse we have heard again and again are when relatively rich people buy into a poor or middlin' rural areas and start demanding zoning changes that they then use to shut down small farmers, watermen etc. Sometimes they expand their lands over those they ran off/ran out of business, sometimes they are just demanding the neighborhood conform to their will. Some will even buy areas next to a public access ways - next to waterways or to a park and then start encroaching...moving their fences over the years until they have stolen public property by common law. Those are the
really bad rich neighbors.
Odd that the article only knew about 'envy' as a problem?
4) Wacky Neighbors?
Wow..what a vague description...and one just fraught with abuse potential.
Some people dress in clothes from other eras or countries, and are excellent neighbors. Some may do ghost hunting. Some may attend costumed conventions with antique weaponry (and practice at home) . Maybe they look for aliens on the weekend or indulge in paintball battles in the backyard (occasionally spilling into yours) ...but they can still be good neighbors....some might ask for a cup of milk every second Thursday for some oddball reason of their own, and yet still be reasonable neighbors otherwise.
Everyone has the capacity to be a wild eccentric in some hobby or other (or else anally weird about their lack of hobbies). What's more, every noticeable cultural difference can be described as 'wacky' by the neighbors...as transferees between North\ South \ East \West can easily testify.
Its only when a neighbor decides that your property is nicer to picnic on than their own, or your ley property lines are stronger so they will have the candle ceremony
there, or they can trespass anytime they like as long as they are riding their horse or chasing hunting dogs, or that their music is something everyone should be forced to enjoy, or that you can't put up a crèche when they've got a giant Buddha in their yard...that there is a problem.
Even then. the problem isn't really the beliefs, the pets, their taste in music, or the hobbies.
Eccentricity in and of itself is no big deal. It only makes life more colorful. Its when someone decides they don't have to respect you or your property rights that this comes up at all.
Actually describing people as 'wacky' is often a prelude toward the sort of respect issues that really ARE the problem.
5) 'The Difficult Neighbor' 
*snort* Every neighbor causing you problems is regarded by you as 'difficult.'
The truly difficult neighbors are those who instigate troubles with other neighbors, who actively gather in groups/gangs (or dribs and drabs) and point you out as someone to mistreat. Maybe they don't even know you. They just think they do...or think that they at least know 'your kind.' They don't like your politics, faith, region of origin, orientation, ethnicity, or simply heard some nasty rumors that made you a good target as far as they were concerned.
People who will use animals to harass you are definitely difficult neighbors. Dogs are the most abused this way. They get sicc-ed on people who aren‘t attacking them to suit their spiteful owner. These dogs often turn mean, bite someone and then get put down. Happens all the time. But other animals & their products are also used, like setting a camel/llama known for distance spitting as close to a neighbor's sidewalks or driveway as possible, or piling up manure as close to the neighbor's property line as they think they can get away with, or actively shooing chickens or goats into your garden (when they aren't yours), or calling the HOA, county, or city with petty or false reports about your property or household.
DH points out that not all such bad behaviour is based in spite. Quite a few misbehaviors (like taking other people's parking spaces for relatives, storing boats & RV's over the property line, cutting down bushes or trees on adjoining properties, gardening on or letting their animals graze on 'unused' lawns belonging to a neighbors) were based in a desire to claim more property rights with simple pushiness than the legal ownership would have conveyed. People like that know they are stealing something from you, and have braced themselves to be unpleasant and to expect you to be unpleasant...but that doesn't mean being extra nice is going to fix a problem neighbor like that. Most likely they will just think you are being weak. You can try plain, respectful communication, but most likely you will be required to exhaust your legal remedies if you wish to see an end to the bad behaviour...or else put up with it until someone moves.
Someone like this is not interested in being a good neighbor.... Make sure that if you make the sort of neighborly gesture the article suggests...like, say, cookies or cake, that you bought it from the bakery and you have photographic evidence that it was still sealed when you handed it over.
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6) Gossipy, judgmental locals making up nasty whoppers are among the worst neighbors of all, since they set you up to be abused by everyone else. Oddly, this author missed that entire category.
Basically, loving one's neighbors needs to be done carefully...possibly at a distance...and is no commoner now then when Christ chastised the world around him for not trying over 2000 yrs ago. Sad isn't it?
This article is better IMHO
& This article just deals specifically with the snoops/nosy gossips out there.
