Stupid answers and Game Shows go hand-in-hand — you generally can't have one without getting the other at some point. Who Wants to Be a Millionaire?, having been on for over a decade in the United States alone, has had more than a few.
Note: As with the other Game Show pages in What an Idiot, some of the following contestants may very well have given these stupid answers on purpose, while others are genuinely stumped and don't know the answer to a question nearly everyone would conlude is simple. This owes to the fact that some contestants do well enough when taking the contestant application test, but when it comes to playing the game on the air, for some reason they fail at correctly answering a seemingly simple question. That doesn't make them any less stupid, mind you, but instead become far more worthy of being here.
In general, anybody who leaves a Lifeline "on the table" (except Double Dip). Even if you think none of your contacts would know the answer, use the Lifeline anyway — you'll get more face time, and you might just be surprised at how knowledgeable your buddy is. And even if you fail, you can at least take pride in that you exhausted all your available options.
In general, anyone who bombed on a first-tier question, which is often insanely easy and typically general-knowledge. Believe it or not, several contestants have whiffed the first question (originally $100, then $500 for the 2009-10 season), which usually had a blatantly-incorrect gag answer for "D".
August 1999: The first contestant who whiffed the $100, Robby Roseman, had the bad luck of getting a question that was unusually hard for that level: "What animal did Hannibal cross the Alps on?" The contestant used his 50/50 to eliminate "Chihuahuas" and "Horses", then of the two remaining ("Elephant" and "Llama") answered the latter. This led to the Fan Nickname of "Llama" every time someone whiffs on the first tier.
On another occasion, a college kid came on and revealed that he hadn't slept in a long while due to the ride to the show, and pretty much had coffee flowing through his veins. He then proceeded to miss the $100 question by saying that the purpose of a surge protector is to protect against water. Is it any wonder why teachers tell you to sleep well before test day?
Circa 2007: This contestant realized his mistake after locking in a wrong answer on the $100 question.
This lady bombed on her $200 question for thinking a period/full stop introduces a list of items instead of a colon.
This guy used all three Lifelines on a $300 question and still got it wrong because his gut was leaning towards the wrong answer from the beginning. (It's also a good example of how the 50:50 may not have actually been "random", and why the audience really shouldn't be applauding dumb contestants.)
It has been established in a few places that the 50/50 does deliberately leave the correct answer and the most-likely-to-be-guessed wrong answer.
December 7, 2009: The height of failure — two consecutive contestants leave with nothing, and the second does so on his first question.
On the Australian version, an elderly man lost on the $500 question due to not knowing what kind of animal Blinky Bill is (a koala) despite being a beloved children's character since the 1930s.
Although this first shuffle-format question was actually the second-hardest in Round 1 before randomization (meaning it would've been worth $15,000 or $16,000 in the older formats), obviously this grad student still wasn't paying attention in class.
One contestant used two Lifelines on her second question — "What type of animal is Garfield?"
A contestant on the French version infamously couldn't identify the Moon as being the object that orbited Earth. When he used Ask The Audience, many of them evidently decided to stitch him up (one of our French Tropers confirmed that basic astronomy is decently taught in schools) and deliberately picked a wrong answer — and he duly went with them. This incident is gleefully used by sociologists as an example of typical French behavior, although that seems slightly disdainful (except for the "stitching someone up" part).
The producers themselves, who asked the question "Which Great Lake after Superior has the largest area?" The correct answer (which the contestant chose) was Lake Huron, but they said it was Lake Michigan, which is the second-largest by volume. Not helping matters was that the question was ambiguous and didn't say "surface area", meaning there was no right answer. The player later returned to continue from that point.
May 20, 2005: During one of the show's occasional "Walk In and Win" weeks where contestants are randomly selected from the studio audience without any audition (itself possibly a stupid move by the producers to begin with), a contestant named Michelle Glover blew all her Lifelines on the $200 and $300 questions...then walked away with $300 — becoming the first (and so far only) contestant in the history of the American show to win a non-zero amount of less than $1,000.
April 1, 2009: One guy who tried to walk away during a Double Dip just as the clock hit zero. Meredith told him that "you know you can't walk in a Double Dip", despite the fact that she didn't state this fact when he used it. (In comparison, during Super Millionaire Regis always asked for a confirmation before using Double Dip.)
However, the contestants are informed of the rules even before getting on the show, and this included the fact that choosing to use a Double Dip meant the contestant was choosing not to walk away, but to guess twice instead. Ordinarily, if time ran out during the Clock format, it was counted as walking away with the total current winnings rather than the bare minimum at that point, but since the Double Dip was in effect, not answering after the clock resumes following the free first guess was counted as an incorrect second answer. This Season 8 contestant also ran out of time during the Double Dip, dropping her down to $5,000.
The guy who said "What part of 'that's my final answer' don't you understand?" to Regis when the contestant was choosing the wrong answer and Regis was trying to help him out.
One contestant on the Czech version was asked about the name of a well-known fairytale ("Ali Baba and the Forty Thieves"). The guy said that he had a "sound memory", proceeded to say out loud the choices (which only varied in the number of the thieves) and put "Ali Baba and the Ten Thieves" as his final answer.
One guy on the Australian show got 11 times 12 wrong.
There was a guy in the earlier episodes of the Regis version who was from Florida ("Go Gators!", he said) and did pretty well... until he got to a question that seemed to stump him. While the guy stared at the question, Regis asked, "Do you want to talk it out?" The guy said, "You want me to talk it out? All right, final answer, A!" Regis replied, "Fast enough, but wrong enough."
A contestant on the Italian version was asked what kind of animal would be found on a perch. With the 50/50 narrowed to "parrot" and "hamster", she said, "the parrot usually stays on a pirate's arm, so it must be the hamster."
The Norwegian version had one female contestant waste her Ask The Audience lifeline on the very first question, only to ignore their input and go with the wrong answer. And it wasn't one of those rare occasions where the question was difficult either...
Early in the US series, a guy was asked, for $500,000, "Which of these is not a Pokémon?" Now, since he was an older man and admittedly had no idea what on Earth Pokemon was, he could be forgiven for walking away, especially as he had no Lifelines left... except that B was Frodo. Even Regis said, after the contestant chose to stop, "Every child in America is screaming at their TV right now..."
Even better, Nintendo Power discussed this in one of their magazines shortly after this episode aired... and listed the wrong answer as well. (They were notorious for being sarcastic in the letters section during this time period.)
Supposedly, one contestant's $100 question in the original US series was "What color do you get when you mix yellow and blue?" The contestant proceeded to ask the audience. 98% gave the correct answer, which makes you wonder if the other 2% were just as idiotic, or if they were just trying to be funny (and also if the contestant was actually that stupid or if he lost a bet or something).
One episode's "early questions" went: "Complete the name of the children's game: 'Duck, Duck...'" The first answer was "Goose," of course, but the contestant said, "It's been a long time since I was a kid...I'm going to have to ask the audience."
In addition to the actual examples given above, an online urban legend circulated in 2007, where a contestant purportedly was asked "Which of the following is the largest?" as her $100 question. The four choices were peanut, elephant, moon and tennis ball. The contestant, so the story goes, proceeds to blow all three of her lifelines, not convinced that the largest – moon – is the correct answer. Her answer: Elephant. (An elephant is the larger to the naked eye when compared to the moon, but the question was going for the largest in physical size and mass, for which moon was the appropriate answer). The actual frame was from the British version of Millionaire?, where the contestant in question did rather well.
Even worse: The contestant, prior to using her 50/50 lifeline, was leaning toward either peanut or tennis ball (the two choices that were wiped out upon the 50/50). At this point, according to the urban legend, host Meredith Vieira has a look of disbelief on her face.