Hard to argue against Pep at the moment, with money the best is Pep without a question. Not only for titles but the way he makes his teams play, completely dominant. I dont think any other manager can achive that even with the same money.
With less budget for me is Simeone, the way he has changed atletico, won the league and was minutes away from winning the champions twice. Even when atletico keep selling their best players (Aguero, Falcao, Diego Costa, Courtouis, Miranda, Arda Turan, Mandzukic, etc) he always finds a way to keep their team competitive. I remember the first time he reached the UCL final ten out of the eleven players of the starting squad were in atletico before his arrival, most of them were nobodys and he transformed them. This season hasnt been great for them, but still is one of the greatest.