Arsene Wenger - he completely changed football in England for the better. He introduced the sport science side of things. Brought in pscychologists , dieticians , etc. to improve the performance of players. Look at some of the fooball Arsenal have produced over the last 5 years , breathtaking , although Wenger is probably more of a mangaer than a coach (Pat Rice being the one who does a lot of the training ground coaching) I'd still say Wenger is the main man.
People are saying that Sven isn't passionate enough to be a manger because he doesn't shout at half time etc. , apparently Wenger never shouts at half time etc. and he's done pretty well.
Not only has Wenger displayed outstanding and beautiful football , he has brought results aswell. The league , FA Cup and so close to the Champions league last year. Sp for me Arsene Wenger best coach/manager around.
Jose Mourinho - has brought a huge amount to England , he inspires his players with confidence and has great tactical knowledge. His interviews are class o watch and the players love him. He's ruthless which is an essential quality to have to succeed in any walk of life. And although many fans (of teams other than Chelsea) dislike him it's only becaue he's so confident and so succesfull , fans don't boo bad players , it's the same for managers.
Finally , Ratherton
your right. Brian Clough shouldn't be forgotten , he was a great coach. Very confident , and correct me if I'm wrong Ratherton
but wasn't one of Brian Clough's footballing philosophies "let the ball do the work" ie. keep the ball on the floor and pass it , so you don't have to do the running