I was just checking out my new Nexus 5 phone, and clicked on youtube. It immediately asked me if I wanted to view it on my TV, so I said, what the heck and gave it a try, and it brought up the names of my TiVo boxes to pick from. I picked the one I happened to be sitting in front of, and by golly, it just worked.
I was shocked.
The last thing I ever saw work without tweaking, and adjusting, and fiddling was gravity: If you let something go, it falls - no tweaking required.
I certainly never had any plug & play hardware plug or play without an infinite amount of fiddling around.
I guess I knew this was supposed to work, but just stumbling across it without thinking about it and having it work was amazing :-).