Monk (Final Fantasy XI)

Strengths

 * Monks do very good damage versus average and low defense creatures and extremely high damage versus Skeletons.
 * High HP total

Weaknesses

 * Monks do very poor damage versus a number of common XP mobs, such as the crab family.
 * Monks do not have a weapon skill that can create distortion until late in the game, which is a player preference created stigma associated with the job.
 * Monks have relatively low defense

Warrior
Until breaching level 70, about 90% of all monks found in Vana'diel will probably be using warrior as a subjob, if not more. There are many reasons why Warrior is so highly favored including the fact that berserk will drastically increase damage over time and it stacks with monk's boost ability for extra weapon skill damage; provoke makes them either good at being a "SATA" partner or an off-tank if things go wrong; and double attack provides an extra increase of damage.

Ninja
After level 70, the ninja takes off in popularity if only because of the advent of "Bones Parties" and other "TP-Burn" style parties where rather than having a tank, hate can bounce between party members freely, all of whom have blink through utsusemi.

Thief
Occassionally there will be a monk who prefers a moderate drop in his damage over time to do more so-called "spike damage." Spike damage refers to damage delt in an an instant, usually because of sneak attack and/or trick attack. To facilitate this, a player must use thief.