The first place I heard "my bad" was in Cartman Gets an Anal Probe and it was said by the new visitor who turned the cows inside-out. So I think it's hella-cool. Has anybody heard it prior to that?
My buddy from San Francisco dropped "cool beans" on me a few years ago, about the time Java (the programming language) was becoming popular. Coincidence?
"Don't even..." Hanging pause. When brevity is required.
"Let's not go there." Reflexive, and somewhat contemplative.
"Let us not go there." Formal, slightly archaic. See also: "Let us not venture forthwith."
"Let's don't go there." Slang.
And...
I have no need to talk to anyone's hand, foot or any particular body part, thank you very much. Please retire all variants of the command "talk to the _______ !"
I think you're barking up the wrong tree objecting to "my bad". I see it as a mordern extention of the "mea culpa". And if its been around that long your grave stone will have decayed before it goes out of style.
Personally, I want to smash things when I hear "anyhoo".
I also still use cool; though I feel very old when I do.
Cool beans wasn't in when it was in. Only ditzy girls used it as far as I can tell.