At this moment in time, and with all due respect to those who might disagree, I do believe at the end of the day we should all speak Plain English.
The Plain English Society has published its list of the most irritating phrases in the English language. "At the end of the day" has been voted as the most irritating phrase in the language. I agree with most of the others listed but have to confess that I do like/use one or two! The two that I do use are "24/7" and "absolutely".