In order to be an effective pro-wrestler, one must perfect the art of the sell.
This is when a pro-wrestler conveys the impact of whatever move they have just taken. For example, when a wrestler throws a punch, it is imperative that the other wrestler stomp their foot at the moment just prior to impact to suspend people's disbelief and make it sound like they're actually being punched. Furthermore, "selling" is also a longer-term thing that wrestlers do over the course of a match, like spending the remainder of a bout limping after being locked in a Sharpshooter.
Sometimes, wrestlers just won't sell at all.
This can be for one of a few reasons - one is that the spot was pre-planned (either by the wrestler[s] themselves or producers) to put somebody over as an unkillable threat, and the other is that... well, the wrestler's just not all that great at wrestling. But regardless of the reason, just about every no-sell is memorable, as they're considered something of an anomaly. Of course, they're nowhere near as rare nowadays as they were, say, 30 years ago, but nevertheless, they seem to stick in the minds of fans.
And these ten no-sells, though they're certainly not the only examples from pro-wrestling's long and storied history, are most-often cited as particularly egregious...