The pop, hiss, and crackle of vinyl. Especially the sound of the needle hitting the vinyl at the start, and that sound it makes as it finds its fit on the grooves. I love that sound.
I’ve got a USB turntable now, and I’m going to try and include that on my mp3-from-vinyl files.
Also, I’d like to tell my 15 year old self how much she will missing having parents.
I miss “Super Saturday” style Saturday morning cartoons that would run from 7am until noon. We’d all wait in anticipation for that day in September when all the new cartoons would debut, and sometimes the networks would have a special Friday night preview the night before the premiere.
Don’t worry, I missed you too 
(sorry couldn’t resist)
The old late night television programming: Grade B westerns, horror flicks, and World War II movies. The Friday and Saturday night shows with musical groups and perhaps a concert film.