There are actually a significant number of productions that you come across, from Germany, France, the UK, and various countries.....so it's not a simple task for an American to pick one favorite. My choice is a four set production out of Iceland.
Naeturvaktin (the Night Shift). It's a short season of twelve episodes....surrounding three Icelandic guys who work or pretend to work at a gas station in Iceland. There's the Marxist-over-educated manager (Georg) who probably should have moved to the old Soviet Union to be happy. There's Daniel, the failure at life guy who acts as a clerk but just can't cut it. And then there's the immature adult pretending to be a 12-year old kid....Olafur. Nothing really happens much at the gas station and it's more of a Seinfeld-type-Icelandic comedy. I don't think anyone on the production team ever expected for this to cross lines and become popular in the UK and across Europe itself.
Dagvaktin (the Day Shift). Things were so successful with the first series of twelve.....that they repeated the formula again. The trio had gotten themselves hired in at some small hotel operation. Georg was the Marxist-manager, Daniel served as the cook, and Olafur....well....he was working on a mega deal to be a successful business man. In this season, they introduced the hotel owner.....an Icelandic gal who was sex-starved and desiring of Daniel. This season went for eleven episodes.
Fangavaktin (the Prison Shift). Shocked at the success of season 1 and 2, they took the trio (minus the Icelandic gal) and sentenced them to prison. Georg now serves as a Marxist-prison-wing manager always trying to wear a prison management uniform and being told that he's an inmate, not a manager). Daniel goes through relationship issues. Olafur.....well....he is still trying to be a successful businessman. There were only seven episodes to this season.
Mr Bjarnfreoarson. This is the last of the four and was a 109 minute movie to wrap up the entire series. Basically, all three have been let out of prison and finding it hard to adjust to life, but truthfully....they just never were going anywhere much before they went off to prison.
Oddly, the whole series consists of only 30 episodes (around a 22-minute production each) and one movie to tie it all up.
If you can find it....it's typically in Icelandic with English-sub-titles, and I would highly recommend it.