Interesting that "Fargo" is the Coen Brothers film that's probably had the most commercial success and is the only film for which they've won an Oscar. (I believe they were nominated for best ADAPTED screenplay for "O Brother", and have never been nominated for Best Director or Best Film).

"Fargo" is certainly their most mainstream and straightforward film, in my opinion. It's an interesting story with well-written, well-acted characters, and it's funny. Their parody of the Minnesota people's dialect is still being copied today in other films and in commercials. The film stays on path, and doesn't delve into the "weird" tangents that some of their others do (i.e. Leonard Smalls in "Raising Arizona", the UFO thing in "The Man who Wasn't There").

Still, what makes their other films so "weird" or unique is what I (and I imagine many others) find so interesting.