Broken Base: For many people, it's the first thing that comes to their minds when challenged to play a board game. For others (in particular, more seasoned board gamers), it's a tedious, rage-inducing game tainted by house rules that gave the entire genre a bad name by causing people to think that all board games are long and boring.
Ending Fatigue: The game has a reputation for being almost endless, but extremely long games are usually the result of House Rules. Oddly enough it's this same reason which is why no one really understands why "free parking" is called that. Once the properties are all bought up, it's somewhere you can land that is free. The instruction booklet includes two sets of rules for shorter games [Short game] (At the start of the game, three properties are dealt to each player, free of charge; only three houses are required for an hotel; players in Jail must exit on the very next turn; the 10% income tax option in pre-2008 North American editions is not used; the game ends at the first bankruptcy, with the winner being the player with the most assets)[Timed game] (The players agree upon the time when the game will end before starting the game; at the start, two properties are dealt to each player, which must be paid for; the player with the most assets at the predetermined time wins) in an attempt to avert this, but almost nobody uses those.
Taken Up to Eleven by "Monopoly: Longest Game Ever", which features 66 property squares* but only 22 properties; buying one makes you the owner of all three squares it represents and only one die, meaning players crawl around the board at a snail's pace. The game only ends when one player owns every property on the board, and even going bankrupt doesn't get you out of the game.
The Bank has 32 houses and 12 hotels (in most versions) because the players are supposed to upgrade their houses to hotels, returning the houses to circulation. The rules prohibit building more houses when all the houses are on the board. This makes it a very profitable strategy to buy lots of houses without ever upgrading them to hotels, as it prevents the other players from buying any.
To make even more sense of this, one hotel requires four houses to be turned in, in addition to the price of the house. Thirty-two divided by 4 is 8, so if you have three monopolies (let's just say Boardwalk and Park Place, and the two monopolies between Jail and Free Parking) and all eight of those properties have four houses on them, nobody can build any houses until you decide to upgrade.
Of course, this is a moot point if you use the common house rule where you can directly skip to hotels even if not enough houses are left as long as you can pay the equivalent price. note And let's not get started with the "infinite buildings" house rule...
If a player gets a non-utility/non-railroad monopoly early and immediately builds houses, it usually quickly cripples his/her opponents.
The orange and red properties, when developed. Jail is the most commonly occupied space. The oranges are 6, 8 and 9 spaces away. The reds are 11, 13 and 14 (and one of them has a Chance card that sends you directly to it). Basically, anyone leaving Jail has VERY HIGH odds of landing on at least one of those properties in 1 to 3 turns.
The Speed Die, by design to speed the game up. The most notable feature of it is Mr. Monopoly; if one rolls it, they take their turn as normal and then immediately move to the next un-owned property, or next property the player has to pay rent on if no un-owned properties exist. A player with most of the board against another player with only a few properties with buildings on them could find the entire game turned around in the bad roll of too many Mr. Monopolies in a row.
"You won second prize in a beauty contest. Collect $10."
The game's reputation for turning even the most close-knit of players into vicious, backstabbing monsters.
Cropping the box-art to have Mr. Monopoly point at the letters "NO". Often used as a reaction image.
Misaimed Fandom: The game was intended to teach the evils and greed of capitalism. Ironically, fans enjoy the capitalism theme in the game because it gives them the opportunity to have endless wealth.
Mis-blamed: Monopoly's infamous reputation for being an overly long game is usually caused by House Rules, the two biggest ones being No Auctions and the Free Parking Jackpot. Games can still be tedious without these, it's not as well-balanced as modern tabletop games, and the fun of trading is only as fun as the people you're playing with, but those two house rules are still responsible for more of the grief than many rants will let on.
"Seinfeld" Is Unfunny: Since it's been the best-known and most commonly played commercial board game in the Western world for nearly eight decades, it's probably not too surprising that a lot of folks have become a little sick of Monopoly by now. Check in at BoardGameGeek.com sometime to peruse the litany of complaints that many folks have with the game — board game enthusiasts are especially annoyed by its ubiquity since many associate "board games" with Monopoly and bad memories of playing it, discouraging them from trying other, much better games.
They Changed It, Now It Sucks!: The major changes that have happened since the Turn of the Millennium saw that kind of reaction from a lot of long-time players. Those include the major graphical redesign in 2008 that ditched the hand-drawn Mr. Monopoly in favor of a creepy-looking CGI rendition among other changes, particularly to the North American edition note (the cheapest properties changed color from purple to brown, the GO letters became black instead of red, the 10% option on Income Tax was removed and Luxury Tax was upped from $75 to $100; to be fair, all those changes were done to put the North American version in line with the UK and European versions, which already had the brown group, black GO, no 10% tax and the £100 Super Tax), the replacement of the iron token with the cat in 2013 and the replacement of the boot, thimble and wheelbarrow tokens with the T-rex, rubber duck and penguin in 2017.
Tier-Induced Scrappy: Railroads and utilities are pretty worthless, often not even making back the money it takes to buy them.
The For Millennials edition was mocked hard for this. If Mr. Monopoly wearing sunglasses, taking a selfie on his phone, drinking from a plastic coffee cup, and listening to music through earbuds didn't give this away, then 2 tokens being a "Tears of Joy" Emoji and a Hashtag, and all the properties and cards being themed after Millennial stereotypes, should.
Ms. Monopoly dives hard into positive discrimination. Female players start with and make more money from passing Go than men, the properties are all things invented by women, and men in turn make more money from "supporting" female-led endeavors. But it still manages to include sexist moments, like a Chance card that tells the player to avoid an "awkward date" by advancing to the Fire Escape space.
Passing up two experienced hosts of the genre (Marc Summers and Peter Tomarken) for a former Jeopardy! contestant who had no TV experience? (To be fair, both had to be passed up for reasons beyond the show's control, but still...)
Having a little person as a living token in the 1989 pilot, though this is more due to how the idea was treated by the producers (Patty Maloney wasn't allowed to speak on-air since Rich Uncle Pennybags was male and an "entity" and Tomarken wasn't allowed to interact with her during the show, an idea he didn't like).