The Majjhima Nikaya is a collection of 152 suttas of a "middle length" covering
a wide range of topics. It has been suggested that the suttas in this collection
were intended as a set of study texts for newly ordained monks as they
pursued spiritual development.
The best way to really get a deep understanding of what the Buddha taught is
to simply read a LOT of suttas. There is a huge variety of topics and a
bewildering array of teaching. But the important points do emerge by
themselves with repeated encounters. The following list is organized into
groups that reflect the order of importance according to my subjective and unenlightened opinion
as to the suttas that stress the important points:
MN 9 - Right View Sariputta teaches the wholesome and the unwholesome, nutriment, 4 Noble Truths, 12 factors of Dependent Origination, and the taints.
MN 10 - The 4 Foundations of Mindfulness This is one of the most important suttas; it outlines the path of practice in wonderful detail. See also DN 22.
MN 22 - The Simile of the Snake Contains not only the simile of the snake, but the simile of the raft, a deep teaching on non-self, a description of the arahant, the teaching of only "dukkha and its ending", abandoning the aggregates, stages of enlightenment. See also MN 109.
MN 24 - The Relay Chariots This sutta lays out the path of Insight. It forms the outline of the Visuddhimagga.
MN 38 - The Greater Discourse on the Destruction of Craving Dependent Origination in detail, the Training in brief.
MN 63 - The Shorter Discourse to Malunkyaputta What the teaching is and is not; the simile of the poisoned arrow.
MN 86 - On Angulimala A mass murderer becomes enlightened
MN 109 - The Greater Discourse on the Full Moon Night Aggregates, clinging, personality view, realization of non-self; see also MN 22.
MN 118 - Mindfulness of Breathing The 16 parts of meditation on the breath, the 7 factors of enlightenment. [Bilingual excerpt here.]
MN 141 - The Exposition of the Truths Sariputta explains the 4 Noble Truths in detail.
MN 26 - The Noble Search The story of the Buddha's quest for Enlightenment.
MN 36 - The Greater Discourse to Saccaka Another telling of the story of the Buddha's quest for Enlightenment.
MN 2 - All the Taints 7 methods for restraining and abandoning the fundamental defilements.
MN 7 - The Simile of the Cloth The Buddha illustrates the difference between a deluded mind and a pure mind.
MN 20 - Removal of Distracting Thoughts 5 methods for dealing with distracting thoughts that may arise during meditation.
MN 27 - The Shorter Discourse on the Simile of the Elephant's Footprint The Training in detail.
MN 53 - The Disciple in Higher Training Ananda teaches the Training in detail.
MN 60 - The Incontrovertible Teaching The original formulation of what became known in the West as "Pascal's Wager".
MN 61 - Advice to Rahula at Ambalatthika The Buddha admonishes his son Rahula on the dangers of lying; the importance of motives.
MN 62 - The Greater Discourse of Advice to Rahula The Buddha teaches Rahula the 4 elements, mindfulness of breathing, and other topics.
MN 71, 72, 73 - Discourses to Vacchagotta The 3 fold knowledges; the simile of the fire gone out; Vacchagotta's conversion, training, and full enlightenment.
MN 121 - The Shorter Discourse on Voidness, An early teaching on how a deep perception of emptiness leads to enlightenment.
MN 143 - Advice to Anathapindika On his deathbed, Anathapindika hears a deep sermon on non-attachment from Sariputta.
MN 146 - Advice from Nandaka Nandaka teaches the nuns about the 6 senses, dependent arising, 7 factors of enlightenment.
MN 148 & 149 - 6 Sets of 6 and The Great 6-fold Base 2 suttas on the 6 sense bases and how fully understanding what is happening with them leads to liberation.
MN 8 - Effacement The Jhanas are no big deal; moral behavior.
MN 13 - Mass of Suffering Sensual Pleasures and the Danger therein.
MN 19 - Two Kinds of Thought Unwholesome thoughts should be replaced with wholesome thoughts.
MN 28 - The Greater Discourse on the Simile of the Elephant's Footprint Sariputta explains the 4 Noble Truths, the 4 Elements, 5 Aggregates which are dependently arisen. "One who sees dependent origination sees the Dhamma; one who sees the Dhamma sees dependent origination."
MN 29 - The Greater Discourse on the Simile of the Heartwood The goal - the heartwood - of the practice is the unshakeable deliverance of mind.
MN 33 - The Greater Discourse on the Cowherd 11 factors of spiritual growth.
MN 35 - The Shorter Discourse to Saccaka A Debate; the 5 aggregates.
MN 37 - The Shorter Discourse on the Destruction of Craving Craving
MN 107 - To Ganaka Moggallana The Training taught by "The Shower of the Way".
MN 112 - The Sixfold Purity Description of the mind of an enlightened one. This sutta uses "consciousness" (viññana) in 4 different ways: as one of the 5 aggregates, as one of the 6 elements, as sense consciousness, and as mind (as the counterpart to body). [It is probably a late, composite sutta.]
MN 114 - To Be and To Not Be Cultivated How to behave.
MN 117 - The great Forty Right View explained in detail via its relationship to the other factors of the 8-fold Path.
MN 119 - Mindfulness of the Body Mindfulness of the Body and its relationship to the Jhanas.
MN 125 - The Grade of the Tamed The training of a disciple is like the training of an elephant.
MN 138 - The Exposition of a Summary Don't get stuck on the senses; Jhanas; non-self leads to non-agitation - cf. MN 22.
MN 145 - Advice to Punna Guarding the senses; "What if someone abuses you?"
MN 147 - Advice to Rahula The Buddha's discourse on non-self that leads to his son's enlightenment.
MN 152 - The Development of the Faculties Guarding the senses.
MN 108 - With Gopaka Moggallana After the Buddha's passing, Ananda teaches 10 qualities that inspire confidence in one who has them; right meditation.
MN 77 - 37 Factors of Enlightenment; Jhanas plus Insight
MN 111 - One by One as They Occurred - How Sariputta became enlightened - version #2.
MN 113 - Thinking that the Jhanas are a big deal is "untrue"
MN 115 - The elements, sense bases, dependent origination, possible and impossible situations
MN 127 - Instruction for the 5th Jhana
MN 128 - Living together, Biographical information; hindering mind states. A source (along with Dhp 1.5) of "In this world hatred is never appeased by hatred;
hatred is only appeased by love. This is an eternal law."
MN 140 - (Late sutta) 6 elements, 6 sense bases, 18 kinds of mental exploration, 4 foundations of enlightenment
MN 144 - A monk commits suicide and becomes enlightened as he dies.
MN 151 - Various aspects of the path.
MN 1 - The Root of All Things - A very difficult to understand non-dual teaching.
MN 4 - Dealing with fear, Biographical information
MN 68 - The Buddha says that he doesn't declare the destination of one who has died to deceive or flatter people, but because it gladdens and inspires the faithful
MN 97 - Sariputta guides the brahmin Dhananjani to rebirth in the Bhrama-world via brahma vihara practice, but is reprimanded by the Buddha for not having taught him teachings that would lead to stream entry
MN 102 - Like DN 1, corrupted(?)
MN 129-130 - Heaven and Hell; 129 includes the simile of the blind sea turtle