I wasn't madly keen on pickled herring when I moved to Sweden but I have to say I love it now. As you say there dozens of varieties. To be honest there's an eye watering number of ways they prepare herring, never mind just pickled.
I used to work at The Steer Inn (I know, I know, I shouldn't boast of my illustrious career for fear of jealousy and retribution) and for some reason they sold rollmops and there were surprisingly popular. A couple of those for a starter followed by a Pearly Fillet (fillet steak and oysters) and I was a happy man. Well, as happy as I could be working in a cauldron and losing every Saturday night for five years.
Put my name down to go to the Falklands but ended up first reserve. If anyone had not gone, I would of.