Re: Mi raccomando!
These days, in NYE/AE "I beg you" would only be used in situations where you are either 1) joking or 2) in dire need of something.
For example, if a cab driver is driving like a lunatic, you might "I beg you, please drive slower or we'll both be killed." Or joking to a loved one, "please, I beg you, no more singing in the shower, I can't take it anymore!"
Real pleading and urgency is communicated by "I beg you", and I don't think it is by "mi raccommando."
PANDAmonium (noun): What happens when posters don't use capital letters and punctuation!