Kenneth Branagh is great as the aloof Wallander, hard to overstate how good he is as an actor in general and as Wallander. The stories are intelligent, based on Henning Mankell's books, told in a slower pace then similar American Detective episodes. The scenery from Southern Sweden is beautiful.
The Swedish versions with Rolf Lassgard and Krister Henriksson as Wallander are really good too and the music is better. Lassgard gives a more jovial characterisation of Wallander, but those episodes are fairly old.
In case you like Wallander, you will probably like "Beck" too set in Stockholm.