Any time a contestant goes for it all in "Beat the Dealer", and picks either the highest possible number for themselves or the lowest possible number for Monty/Wayne.
Anybody who won the Super Deal in either era.
The last episode of the 1971-77 syndicated run, and by extension the "classic" 1963-77 era. Besides there not being a Zonk in sight (specifically, at no point was there a Zonk even present during the whole show; everybody was guaranteed to win something), it ended with a Big Deal win.
On a more fun note, the show started with Monty's daughter and son-in-law, Joanna and Paul Gleason.
In the original version, it wasn't unheard of for enough traders to decline going for the Big Deal that Monty would eventually start asking Zonked contestants to compete for it (remember, the original rules allowed for two separate traders to play). Any contestant who went from being Zonked to winning the Big Deal would definitely qualify.
In the Wayne Brady revival version, during Monty Hall Week in 2010 (where Hall returned to do one deal a day for a week), Monty's deal on March 24 was the updated version of "Monty's Cash Register", the "Cash Board". In the game, a couple is given a board with 15 cards — 13 are dollar amounts, two are Zonks. The object for the couple is to keep turning cards until they collect $1000 of the available $1800, at which point they also win a car — as long as they don't hit the Zonk first. On this playing, the couple turned over the Zonk with their first card. Monty, pretending to call an audible (but using the consolation rule from the old Cash Register game), told the couple that they could turn another card. If it was cash, he'd double it. If it was the other Zonk, they got the car. Of course, since this is on the Awesome page, you know what happened next.
This feat was repeated on December 8, 2016, prompting Wayne to say that this was only the second time this had ever happened.
On October 24th, 2012, a contestant plays a game called "The Great Escape" to win a car. The object of the game is to use as many keys as possible in a time limit in order to open a glass box that contains the car keys. There's 15 keys in total and at most, you can only get up to 30 seconds to play (from 15, you are given $1500 to start, and can give back $100 for an additional second). The contestant picks her first key to start off with and as soon as the game started, she unlocks the box. In the history of the show, no one had ever picked the correct key on the first guess.
It happened again less than a month later, on the November 20th show, when an entire family was called up to play.
It happened a third time on the Jan. 30th, 2013 "Twitter" episode, when the game for the contestant to play was chosen beforehand by voters online.
The occasions where a contestant gives up a car for the Big Deal and wins it. So far it's happened five times on the Brady version - once for $23,002, the other four times for another car.
For the week of May 6-10. 2013, Publisher's Clearing House offered $20,000 per day in one of the show's deals. Every single day, someone won the 20K, including the show's first ever win in "Smash For Cash" on Monday's show.
On June 7, 2013, a contestant playing Car Pong not only gets the ball in the CAR cup on his first throw, he gets a second ball in the cup! Sadly, the player was only eligible for one car.
During the week of June 17, 2013, a contestant has a chance to win a car (of course, she doesn't know it yet). She passes up a chance to look behind the curtain to keep an envelope Wayne has given her. The car is revealed. She passes up a chance to take the prize in the small box, choosing again to keep the envelope. Turns out, it was a second chance at the car. He then offers her the Big Box. This time, she gives up the envelope, which contains a zonk. What's in the Big Box? Yep.
One of the games played during the 2015 April Fools episode was Plinko.
On the December 20, 2017 episode, a new rule was in effect for the Big Deal in which one of the doors had an envelope attached to it containing a bonus prize. This led to a very memorable Bait-and-Switch; the contestant (who was the top winner with accessories) was steered towards Door @2 with the aforementioned envelope. Behind a door was a spa, which did not seem like the Big Deal ... until Wayne opened the envelope, which contained $15,000 in cash!