Nationstates (the actual nation-building simulator) contains examples of:
Anarchy Is Chaos: Played straight. An anarchist nation is described as "in a state of perpetual fear, as a complete breakdown of social order has led to the rise of order through biker gangs." Averted by many roleplayers though.
Author Appeal: The name of the nation, the type of government and its leadership (Monarch/President-for-Life/Sporting Superstar/Chief General/Jedi/Sith) is all named after the creator. It's their nation, after all.
Author Avatar: Pretty much the premise of the whole thing. Not all players though. One player uses it to play as different characters than himself.
Big Brother Is Watching: Comes up as an issue in gameplay frequently. Subverted by certain highly libertarian nations, some of whom don't even bother to conduct a census.
Drill Sergeant Nasty: One of the issues is soldiers complaining about sergeants forcing them to crawl through muddy minefields and climb grease-coated walls. You can side with the grunts or the sergeants, or eliminate training altogether and send out troops who don't know how to shoot, or start raising children from birth to fight.
Follow the Leader: New nations will sometimes have a striking similarity to movies that have come out recently (and some old nations take from popular culture as well, without much alteration in many cases).
Gambit Pileup: See the NS entry on the TXP page. Roleplays tend to turn into this once they've been alive for long enough. Regional political structures often do it right from the start. There are numerous players trading favors and outmatching each other to get World Assembly resolutions passed or killed. Most regional alliances are set up as growing space for these. The more branches of the Broken Base one is familiar with, the more it appears that the entire game is one big Gambit Pileup that's been building up for eight years.
I'm a Humanitarian: One of the issues gives you the option to legalize cannibalism in your nation.
It Makes Sense in Context: Probably three-quarters of the forum-related stuff on this page, especially nation-specific examples, fall under this.
Take a Third Option: Even when you feel an issue could only have two logical solutions, there's often another option that may or may not make sense. Example: allow public nudity, ban public nudity, or ENFORCE public nudity. Others are just a nonstandard extreme/ideal that would be really hard to bring about in real life. Not to mention you can just dismiss the issue altogether if it appears to be Failure Is the Only Option.
Non-Entity General: Originally played straight, now merely optional with the addition of nameable leaders.
Privately Owned Society: With the recent addition of graphs, you can now see your nation's economic division between private and public companies.
Ripped from the Headlines: Quite a few of the issues; one referring to a particular Supreme Court case was written in less than a week. A lot of the time, when a real life tragedy occurs a whole bunch of copycat R Ps emerged with similar things happening to their nations.
Running Gag: "Repeal "Condemn NAZI EUROPE" " and "Victory for gatesville!" are becoming increasingly common, and slightly annoying.
As of late 2010, the orginal "Condemn NAZI EUROPE" has finally been repealed, with a new condemmation in it's place. About time, too.
Speaking of the WA, we might as well mention Christian Democrats' various and futile attempts to ban abortion via WA, and promptly getting laughed out by everyone else.
Shout Out: The "What's in a Name?" issue directly references The Prisoner, with a suggestion that the nation's children be given numbers instead of names.
"A Grave Problem" references Soylent Green, by having an option to put corpses in fast-food burgers.
"The Sky Is Falling": "A particularly bad spate of bombings, hijackings and snakeattacks aboard airline flights has crippled the air travel industry in (your country name here)."
The "Please read: A personal appeal from NationStates founder Max Barry" banner promoting Machine Man is a pretty obvious reference to the "Please read: A personal appeal from Wikipedia founder Jim Wales" banners on The Other Wiki.
The unit of measuring how Atheist a nation is is the "Dawkins".
"Voter Apathy Rising But No One Cares": People are too apathetic to vote, and one of the options is to energize people by putting "POWERTHIRST [TM] to the national water supply!".
Skeleton Government: No one wants to make up and explain all government ministries and offices.
Super Soldier: Selecting the right answer for a certain issue will result in your soldiers becoming this. This is also common in Future Tech nations such as Bajireyn
Teens Are Monsters: If your nation is hard enough on youth crime or has big enough problems with it, that gets a special mention.
Videogame Cruelty& Caring Potential: You can either make your nation the aforementioned Utopia, or a "Psychotic Dictatorship" where you refer to your citizens as "Your Little Playthings" and the phrases "Political Freedoms" and "Civil Rights" do not exist in your vocabulary.
Artistic License - Economics: A somewhat simplistic economic engine leads to oddities such as nations with the strongest possible economy ratings having 100% tax rates, no private sector, and no government funds spent on economic production. And that's before we get into the economic models some players propose their nations run on. Some nations even deliberately fail at economics to avert Mary Suetopia. Or become one.
Zerg Rush / Voted Off The Island: You can't go to war with other regions in the actual simulator. However, you can get a large group of nations on your side to join a region, have them vote your nation the one in charge, then kick out the original members. It's cruel, but not against the rules.
The region & forum-based roleplaying form of Nationstates contains examples of:
Banana Republic: Various nations fully embrace the cliche of a third world nation with the corruption, good weather and banana plantations you would expect. Or insist that their nations are second world nations with pretty much the same characteristics.
Church Militant: While less common than fascist or communist regimes, some nations do intertwine their military with a religious background.
The nation of Tergnitz is known for having a Church as the fourth branch of government.
Con Lang: Some people actually designed the language for their nation instead of using an existing one or just implying a different one is used. See here for a list of NS languages.
The Ukkeld language, written by Astholm, is in development, a sort of mix of Old English, Old Norse and Turkic.
Cool Boat: Many people design their own ships. Especially prevalent in future tech roleplays.
Cool Plane: Played straight by damn near everyone in modern tech roleplays, most of whose Air Forces include the F-22, F-35, YF-23 or Sukhoi PAK FA.
Some people go out of their ways to design new aircraft, in case real planes just aren't cool enough. Especially in Sci-Fi R Ps.
Sometimes subverted by communist and eastern bloc nations, who may well still have Mi G-21s and the like in their air forces.
Corrupt Corporate Executive: Played straight and averted, sometimes within the same nation. Sometimes it seems that this is all some nations are. There are even certain regions to cater to these nations.
Crapsack World: Perpetual war, nuclear and chemical exchanges, and genocide a go-go, baby!
Unless you play against Van Luxemburg or New Azura, both of whom seem to go for semi-realistic play.
Easy Logistics: A global map doesn't exist. Ships leave port and arrive at their destination a post later. Generally more experienced RPers try to factor in logistics in their equations.
Semi justified in FT since there is FTL travel involved and it varies from a day to hours for some nations.
Enemy Mine: Happens a lot. International politics can get very convoluted, much like in real life.
Enforced Cold War: Lots in roleplay, mostly because there's no way to actually force someone to let you invade them. Regional wars sometimes escalate into this when enough regions get involved.
Everything's Better with Dinosaurs: Saursia and Whairtia, for different reasons however.
False Flag Operation: Not often, but people do it sometimes. Hard to pull off in a forum environment for obvious reasons, at least against the will of the target.
Possibly subverted in Ryouese Black Island's recent RP in which he changed his ship from a Freekish flag to his own. People worried less and laughed more.
Full-Circle Revolution: Nations can and have gone from being a Monarchy, to a Socialist People's Republic, to a Fascist Dictatorship and then back to a Monarchy all within the same thread.
I Have Many Names: Astholm, although these are just functional ones, designed to provide a lifelike context to the action in some cases where he won't use his (their? it's a House Pseudonym) main nation.
I Know You Know I Know: Regional politics tend to turn into this alarmingly quickly, at least when war is involved.
Any FT nation not from (The many, many fractal) Earth(s) technically applies, go even further and even Humans count.
Informed Ability: Although almost everyone claims to have competent politicians and generals, many do not succeed in making this believable. Probably because they're not competent politicians and generals.
Informed Flaw: If there is supposed to be a notable flaw, then there is pretty damn good chance that it will not get in the way when things get serious.
Improbable Weapon User: The invasion/defense community. The game doesn't have an officially supported war system, and so a niche population of players hacked together a combat mechanic out of what amounts to bureaucratic white noise.
Better Than It Sounds - the resulting political simulation is probably more realistic than most games deliberately created as such.
Jack Bauer Interrogation Technique: There's an issue that allows you to let your military/law enforcement agencies torture people. It's also done in roleplay quite often, with variable quality.
Kudzu Plot: The histories of some nations would confuse even the writers of Lost. On one of the off-site forums, they have nations whose histories are as professionally written as in Real Life.
One could argue that Magic A is Magic A does apply, but only within these regions.
Martyrdom Culture: Too many examples to list. Just about everyone has their people more than willing to become a hero of the Empire/Republic/Confederation/Kingdom etc.
Mary Sue Topia: Somewhat averted by the game itself, which attempts to indicate that all nation types have their drawbacks, but often played painfully, painfully straight in roleplay.
Noob: You have no idea the level of hate players who have joined in the past 2 years get from those who have been playing for more than 3-4 years. Or from those who have been playing for more than 5-6 years. Or those who have been playing since the game started.
Nuke 'Em: Carpet-nuking is a valid tactic at times. Though usually subverted, as the mere threat of a nuclear weapon is enough to cause a massive flame war.
One Federation Limit: Averted at the beginning by the limited choice of standard state types - Federation, Kingdom, Prinicpality etc. But once you can make up your own, the sky's the limit.
Paid Harem: It pops up from time to time, most commonly with a Sex Slave scenario.
Patchwork Map: People will slap together a map with disregard for their climates. Or for national borders, in the case of nations that lay claim to the same real estate on Earths' continents. Amusingly, this has led to dozens of different versions of Earth for people who insist on having their preferred chunk of land.
President Evil: It is more fun to Role Play a completely evil leader than a nice democratically elected president, thus many nations are ruled by mindbendingly evil dictators. Most nations fail at it, and just seem like a 12-year-old just finished playing Grand Theft Auto.
Considering the demographics of this game...
Well, F7 anyways. The average NSer is in the 18-30 demographic, I believe.
Product Placement: The game was created to advertise Jennifer Government. There even exists an issue referring to the book, which among other things allow you to ban it in your nation.
Conveniently enough, if you bought any of Max Barry's books, you can use the "Remove Ad" button to get rid of the ad banners.
Psycho for Hire: Quite a few nations that are essentially big mercenary companies are like this.
Putting on the Reich: Why invent a new flavour of evil when you can just use a historical one?
Redshirt Army: Poor bastards who get steamrolled. Many communist nations have these.
Retcon: More likely than you'd think. This happens quite a bit when someone gets bored with a roleplay and wanders off without bothering to finish it, or when someone doesn't like the way a role play is going. Given that players are allowed to ignore anything they don't like by the site rules, this can be a source of frustration for some, as there are no permanent consequences unless a player is willing to allow them.
Astholm nearly retconned Celsan, but decided it wasn't worth interfering with what was canon.
Roma: Traditionally the Butt Monkeys of the real world, Gypsies seem to have come into their own on NationStates... there are several Roma-ruled nations.
Rouge Angles of Satin: Sadly, happens quite a bit. Though there are some really good writers on this site's forums, there are some very bad ones too. Rarely will a bad writer on NS improve, and most good R Pers were already good from the get-go.
Sex Slave: A Berserk Button for many, given it's usually done in rather poor taste.
Shout Out: There are many, many nations that copy things from various fictional works. The Celsan Vextra being a Shout Out to the Opel Vectra, albeit with the "X" factor of its name.
Shown Their Work: A substantial number of players have put quite a lot of thought into their nations, and it shows. To a smaller extent, some people spend months and months designing tanks, ships, planes, and other items for their fictional militaries to use.
Astholm does this trope to an average level; his designs may be unoriginal, in styling terms, but at least he gets the car technology right, well, interiors and running gear, if not engines.
Stupid Sexy Flanders: With Spanish soccer player Fernando Torres in the Flanders role. Ask the sports roleplayers.
Sukhomlinov Effect: Subverted. Some of the better militaries are extremely fashionable.
Super Soldier: A popular trope that is rarely done well.
Tank Goodness: Many players design their own tanks, practical or not. Some also like using tanks from their favourite games and movies. If it's been on paper or screen, it's probably shown up here at some point.
Lyras stands far above everyone else in this department.
The Revolution Will Not Be Civilized: It is rare that any kind of political or economic turmoil, not matter how trivial it may seem, does not end up turning into some form of armed conflict.
Those Wacky Nazis: All Nazi-based Nations and Regions. There are a lot, and most are incredibly stupid. Some have even been condemned by other nations. Most characters in character R Ps have this, although not all are successful in playing it straight. Or well.
The Wiki Rule: The site has a dedicated Wiki for all member nations to expand on their nations called called NSWiki. Some nations break away and create a Wiki solely for their nation.
Utopia: Many non-evil nations are the vision of the player of a perfect government. Some of the evil nations are also their player's version of a perfect government, even if it horrifies other players. See Dystopia.
War Is Glorious: What everyone would like to believe. Thanks to state propaganda, many populations believe in this absolutely. Most bad R Pers will often play this straight and make a nation full of chest-beating nationalists.
War Is Hell: Corps sized formations wiped out in under 10 minutes by artillery bombardment, mass use of nerve gas, napalm and landmines, aerial bombardment that lasts for weeks. God help you if you survive and get captured.
We Have Reserves: Who cares about casualties anyway. They're all just statistics. Many players pursue a zero sum course of action— fight to the last man in the nation regardless of anything.
The Scourge Of God: Common with alot of F7'ers, particularly The Nuclear Fist.
It Got Worse: Almost always happening in F7. The Nuclear Fist tends to bind the above two with this regularly. Hath as well, sans the Communism of course. Unilisia (when she is around) tends to be a catalyst of this trope.
What's Up, King Dude?: Mushet, the official king just hanging out, you can talk to him, argue with him, even steal his crown. The same almost goes with Hath, but with Hath if you mess with him there will be consenquences
Guy In Real Life: So far we've had two confirmed (uncovered) Guys In Real Life; Old Erisia, who pretended to be a girl until his male identity was uncovered when he posted his picture, and Baron Lords, who had a puppet account he used to pretend to be his nonexistant twin sister Chaos masters and continued to roleplay as her after he was found out because 'It's more fun that way'.