I've posted these before in a similar thread but two expressions I really despise are:
"quantum leap". To me this suggests the smallest finite change that is physically possible so I don't find a quantum leap in, say, performance, all that exciting
And another is "reaching a crescendo". As even a lapsed musician like me knows, a crescendo is a gradual getting louder, so "reaching a crescendo" would mean you've got to the bit where it is about to start to get louder. It does not mean "the loud bit" or "the exciting bit". The actual crescendo may only go from pp to p (pianissimo to piano - very quiet to quiet)
As an aside I one had to give a presentation to a group of fairly senior managers about some technology I'd been looking into. I think I was last on the agenda so they may have been a bit jaded by then, but I saw them giggling about something then one of them owned up they had some sheets printed up for "bullshit bingo" where they'd tick off the various management cliches. I was a bit bit miffed as I'd put a fair bit of work into it and had had been asked to do it rather being an agenda I was pushing as such so I grumpily commented "you'll not get any from me" and I'm pleased to say they didn't get a single one