The main, most popular build for Monks is the following:
FoT/Thunderclap + SW/Cyclone
Very effective, best used with dual wielding and high (30%+) critical hit chance. The passive skills help survivability, sometimes resolve is changed into something else (fleet footed, combination strike). Works particularly well with Life on Hit and Attack speed gear.
There is really no much variations to the theme. Sometimes one between Flashing Light and Breath of Heaven is changed into Seven Sided Strike with Fulminating Onslaught, even if the attack doesn't perform at best with two weapons.
The second efficient combination is:
Tempest Rush + FoT Thunderclap
Fast farming. Essentially Tailwind and Fleet Footed are added to the previous setup, in order to provide great speed between the mobs. Once you approach the big pack, you generally attack with FoT Thunderclap, generate some Cyclones and spirit and then move fast to the next opponent.
Usually played by strong players with expensive gear (clear advantages with 4 pieces Inna's set) it however needs some extra care when choosing gear, since some spirit regeneration (weapons and/or helm) is required.
Apart from these builds, nothing else exists. Me and some friends are trying out an extreme version of the Tempest Rush concept:
Permanent Tempest Rush
all the spirit generation comes from items and skills, not from attacks. Two buttons for attacking: Tempest Rush for general use and SSS for elites. No defensive skills, since you move so fast and hit so hard that you don't need them. Gear and passives are all pointing towards the spirit+movement speed direction. Pickup radius increase necessary in at least one piece of gear.
Needs however very high DPS to be effective (I do Act 2 with around 75k unbuffed) and a 2-hander (skorn or ideally a similar Daibo).
Does any other efficient build even exist?