I can (and regularly do) sing the chorus to Shaddap You Face (much to the consternation of my wife, the cats, and passing strangers).
I also hum Baltimora's fabulous Tarzan Boy very loudly every time my train pulls into Baltimore station. I can't help myself. One day Amtrak Police will remove me.
Also, Bonnie Tyler's Total Eclipse of the Heart, you get that in your head, it takes glorious weeks to get rid of it. When I die they're going to have encase my iTunes library in concrete for next 40,000 years to make it safe.