Furuhata Ninzaburo Season 2

This is very much like a Japanese version of Columbo (long-running 1970s American detective show with Peter Falk). If you like one, you will probably like the other as long as the language barrier doesn't stop you.

After watching this, get the minor spin-off with Nishimura Masahiko and Ito Toshihito. It's not a real show; they just have some fun with it, and it's hilarious. I think it's called "Imaizumi," but it doesn't seem to be in the JDorama database.

This is the greatest series ever (in my opinion). Tamura Masakazu plays Furuhata Ninzaburo, a rather eccentric detective you always dresses in black. Along with his sidekick Imaizumi, who is completely useless and in many episodes either gets in the way of Furuhata or even gets in serious trouble but is still Furuhata's best friend, he makes the criminals with their well thought out crimes stammer unable to give an answer that makes sense to Furuhata. He immediately knows who the murderer is upon meeting them and continues to follow and bother them with his amazing deducing skill. His characteristic is to slap Imaizumi on his shiny head and ride to the scene of the crime on a bicycle while constantly forgetting his coworkers name. At times he is a charming gentleman and at times he acts like a complete idiot but in the end, he pushes every suspect into a corner as the greatest detective in the world.