OK, answering the OP’s question about what candy bars taste “gourmet” to me, as opposed to listing my favorite candy bars, I’d have to agree with those who nominate Skor.
Yup, I know. Luckily it’s toasted and completely subsumed by the peanut butter.
When they were made (or just distributed?) in the US they were made (same caveat) next door to where I worked. Every time I went into their outlet shop there’d be some truckdriver asking if they had any “Schoolboys” that day.
Wife tried to force a third of one on me–it was hot and I was driving so a candy bar was a bad idea–and all I could say was, “That’s a Forever Yours.” They’ve always been her favorites, so if she weren’t diabetic daughter and I wouldn’t have gotten our thirds.
These and Star Crunches. 
Dark chocolate Bounty is the one I prefer over the milk version.
I used to like various Cadbury things until Kraft shat all over the formula
Another shout out for Little Debby – I hit them and Tastykakes up when I go back to the States. Other than them, though, I can’t stand the taste or scent of American/Hershey’s chocolate anymore. Smells just like sour milk/vomit now; terrible taste.
They sell a similar bagged sweet around here in the 75 cents/2 for $1 racks that’s coconut with a sort of vanilla candy goo coating. I love 'em, but only have a bag or two a month.
My fav candy bar varies from day to day – it’s usually Reese’s or Milky Way, but sometimes I feel more like having a 5th Ave, or a Mounds.
Guilty pleasure time: I occasionally enjoy Circus Peanuts, which are among the least-liked candies in the USA.
I don’t eat candy very often, so I make it count.
My lifelong favorite, by far, is Snickers.
Close second place- Butterfinger
Backups:
Almond Joy
Caramello
Mars (now Snickers Almond in USA)
I find anything reeses to be addicting because of the peanut butter. It isn’t the chocolate that makes reeses so delicious.
God bless you. I LOVE Neccos and nobody in my family or circle of acquaintances understands why.