Agree, it's pretty crucial to watch the first one. I think it's worth the effort/spending though; it's, as a Guardian review said, 'flinty', but utterly absorbing. Excellent acting too.
I quite like The Crimson Rivers (French). Crimes in various picturesque rural parts of France, usually with a killer 'inspired' by religion/myth etc who kills people in symbolic kinds of ways. The leads are two detectives from Paris who spend a good part of the episode complaining about the local accommodation/food/hapless police and supporting team 
It's a bit hokey (DP says it's real-life Scooby-Doo) but I find it enjoyable.