There was a young lady on CBS TJW named Isa that cried when she lost. Jack tried to pretend nothing was happening, other than to say "I can see you're a little upset" and reminded her she still won prizes.
There was a lady on Blockbusters, who was part of the family pair. Her answer was not accepted, because her pronunciation was WAY off, but when they said "no", she looked visibly pissed off, giving the producers an evil eye, and looked very angry when they lost.
On MG 90, during Halloween week, there was a contestant that gave the answer "lubricant", but the answer "oil" was not accepted (because lubricant was a general answer, and oil was more specific) but most of the panel said oil. He looked upset, but Ross explained they couldn't match general answers with specific ones. (Using the logic of matching "food" with any food the panel might mention)
On one ep. of TPIR, there was a guy that showed no interest at all when he was called on down, and his demeanor was no different when he lost on Hole in One, and later won the showcase.
On another TPIR, there was a 10 Chances player that cursed when she got a price wrong. Bob laughed and said "I'm glad have the mike, because I heard what you said!"
On The All New LMAD, there was a lady dressed as a clown. She was offered 500 dollars or a curtain, and sensing there was something better than 500 dollars, chose the curtain, and got zonked with 3 pigs. Monty saw she was upset and tried to console her. At the end of the show, Monty approached her and asked her 3 very simple questions about the 3 little pigs, and she ended up winning 300 dollars. She was happy after that.