CFI/CFII/MEI around 850 hrs.
I've had a couple close calls. One I never saw but was concerned none the less when a center controller descended a G-IV in front of me in a Mooney M20J flying from Palm Beach, FL to Columbus, OH. I'd been in the clouds for about an hour and in pretty good precip for about 10 minutes. His voice became abrupt as he called out a traffic alert, I peered out the window which left me with just enough visibility to barely see my spinner and rain streaking back on the windscreen. I reply "I-M-C" and the G-IV says I'm on TCAS and its one of those times when the TCAS says one thing, the controller says another. The G-IV listened to their magic box and kept up a descent and I just crossed my fingers. An absolutely helpless situation for me to be in. I didn't like it.
I had another time when flying traffic survey in a yellow 172 with a smiling sun wearing shades on the nose and tail. I was orbiting an accident in Columbus just south of Polaris parkway on the Interstate 71/270 split. I was setting up to roll out back on 'the route' which is a bit of an offset figure 8 and just as I rolled wings level in front of me was one of Ohio States 152s. I could see the smurfy paint scheme, the little black 3" numbers on the back signifying which "buckeye" it was and the left seat pilot had blue Telex headsets. I'd come out of my turn inside 100 yards behind the 152 and was closing. I diverted right about 30 degrees and called Ohio State tower asking if they'd like to inform me of any traffic in the area. Turns out the 152 had not turned on his transponder and State Tower's radar didn't even have them as a primary target 7 miles from their airport.
I've done some other things that in hindsight were less than perfect ways to ensure longevity in life...but they were fun none the less and never felt out of control. I do not condone these actions and in no way encourage others to attempt them on their own
For instance: