I admit to the following:
I often say LOL out loud, instead of saying "damn, that was funny" or some similar pharse. But I pronounce it el-oh-el, sometimes with an expletive in the middle, instead of as a word.
I sometimes say eye-eye-ar-see out loud and I frequently find myself writing IIRC in office memos, along with AFAIK.
Several times, I have used CC on my radio in the middle of fighting fires, when it's a VERY BAD time to be confusing people

Once in a while, I'll say oh-tee-way, not OTW or "on the way".
That's it for acronyms. As for other terms, the word "vulch" has become part of my everyday vocabulary for whenevery somebody or something really splatters something rather defenseless. Watching hockey or football on TV, I'll say "great vulch" instead of "good hit". But I also use it at horrible vehicular accident scenes, which isn't so funny, even though a number of my colleagues have started saying it, too. That and "gibs" like from FPS games. Like the other night a woman got run over by a 65mph 18-wheeler and was strewn over about 200m of highway. It was something of a shock to hear my coworkers saying things like, "Damn, that truck vulched her good!" and "Hey, I found some good gibs over here", and know they got that from me.