For my money the better of the two classic Indian verse-epics, the other is the Ramayana. At over 220,000 lines (arranged in couplets), the Mahabharata weighs in at four times the length of the Ramayana, and every chapter is packed with happenings, many with the dramatic force to wake the somnolent peanut gallery. The Mahabharata is devoid of the idealized characters in the Ramayana, its heroes are mercifully flawed and often bring their own doom upon their heads. Its villains are family, and it deals with thorny issues of duty, faith and morality. All in all a rip-roaring read, often compared to the Iliad.
Another factor in the Mahabharata's favor is that it has a bigger, more bloody battle at the end (on the plains of Kurukshetra). Just prior to the battle, one of the gems of Vedic philosophy is woven into the tale as Krishna and Arjuna have a dialogue on the necessity of war, the true path, action vs. inaction and the meaning of life. That's the Bhagavad Gita as related by Krishna on the battlefield of Kurukshetra to Arjuna. Arjuna hesitates as he considers the prospect of massacring his cousins, teachers, elders and friends in battle, Krishna convinces him of the righteousness of his path.
The structure of the Mahabharata as we now know it was likely nailed down in the 4th century AD. It probably started as an oral tale, oft repeated, ever-lengthened, a growing thing unto itself. It relates events that are said to have occurred around 1500 BC, but such dates are always suspect. The Mahabharata is far more self-referential than a story crafted mellenia before post modernism has any right to be. Ganesha (the elephant headed son of Shiva and Parvati, and great lover of literature) is said to have written down the Mahabharata as it was related to him by Ved Vyas. The story is a behemoth, with thousands of distinct characters.
The Mahabharata is more deeply woven into the fabric of Indian culture than any other story. It's influence is everywhere. It has contributed a fair number of well-beloved gods/incarnations to the Hindu pantheon, chief among them is Krishna. The frequency of common sayings in most Indian languages which are derived from the Mahabharata is comparable to the idiomatic use of phrases from the King James Version in English. Names of characters from the Mahabharata are an unending source of names for the seemingly endless numbers of Indian children born each year.
The tale (skipping some preliminaries), runs something like this. A long time ago, in a land not so far away, there dwelt two half-brothers, both princes of the realm. Pandav/Pandu (the younger) marries Kunti and Madri, and has 5 sons (the five, later to be six, Pandavs/Pandus). The three by Kunti are powerful type casts, each an incarnation of a different quality. Dhritarashtra (the blind, vaccilating, elder brother) weds Gandhari, who makes up for quality with quantity and has a 100 sons and one daughter (the Kurus/Kaurava).
The Kurus and the Pandavs aren't particularly enthralled with each other. The question of succession lays bare the animosity between the two camps. On a gamble (with loaded dice no less), Yudishtra manages to gamble away their kingdom, his brothers and Draupadi too. Draupadi is shamed by the Kurus in public (saved from being stirpped naked before all by the deus ex machina in person of Krishna). Eventually, the Pandavs head off into exile for 13 years.
Here we have the requisite rustic and pastoral episodes intermixed with tales of the Pandavs wandering through remote forests. At the end of their exile, the Pandavs return to reclaim their kingdom. But the Kurus aren't going to give it up without a fight.
Now we have the immense battle on the plains of Kurukshetra, which is described in much detail. Unsurprisingly, the Pandavs win.
The primary characters (no, I'm not going to list all the Kuru brothers):
- Karan: Kunti's eldest son, the progeny of the Sun-god Surya, born out of wedlock, abandoned by his mother, raised by adoptive parents of low-caste, scorned by all, superior in skill and learning to all, the one who sacrifices life. The most conflicted, difficult, important character in the epic.
- Yudhistira: the righteous, also called Dharmaputra (son of Dharma). His claim to fame is that he cannot tell a lie.
- Arjuna: the brave. Lion-hearted archer, ever fearless, yet racked by his own sense of right (see the painful convincing job Krishna has to do in the Gita).
- Bhima: the strong. Carries a mace, marries a demon, perhaps serves as inspiration for Mr. T.
- Nakula/Sahadeva: The two sons of Madri, generic good guys.
- Draupadi: Panchali, or wife to all five Pandavs. Polyandry wasn't common but there was a misunderstanding with Kunti, and the righteous Pandavs could never bear to disobey their mother, even when she spoke out of context. There are other women that the brothers marry at various points of the epic.
- Krishna: incarnation of Vishnu, irrepressible ever-youthful thief of curd and milk, lover of beauty, the blue-skinned and haloed, ostensibly the central character in the epic, especially if you believe the entire story is simply a vehicle for understanding the Gita. He is also the inspiration for the Hare Krishna Society, whose members can be seen dancing through airports all over the world in their orange robes when they aren't standing at the street corner handing out copies of the Gita.
- Bhishma: uncle to both the Kurus and the Pandavs, forced by a vow made to his father he sides with the Kurus.
- Drona: acharya (teacher) to both the Kurus and Pandavs, Arjuna is his great favourite yet he fights with the Kurus drive by a sense of duty.
- Duryodhana: eldest of the Kurus, the one whose ambition and unrequited pride drive the story.
- Sakuni: the evil scheming uncle who tears the Kurus and Pandavs apart.
There are many ways to read the Mahabharata. The Kurus and the Pandavs are sometimes said to represent forces that exist in each society and individual, and the Mahabharat is an allegory for a inner war between right and wrong. Others claim the story is a history of the Aryan conquest of much of Eurasia. I prefer to believe that the story was a vehicle to both educate and entertain the masses in camps and villages through the ages, invented by thinkers of great imagination and polished over the centuries.
A great sense of righting a wrong runs through the entire text. It rails, confronts and lays bare the terrible legacy and injustice of the caste system in the stories of Eklavya and Karan. It demonstrates how the good can be taken advantage of by the devious. It makes a compelling case for immersing oneself into the world as opposed to asceticism. Due to its complexity and range, it hasn't been successfully co-opted by the nationalist, fascist, aryan-supremacy crowd that is ascendant in India at the moment (unlike the Ramayana).
All in all, one of those things you've got to read before life releases you from its grip.
There is another writeup in this node that has a better plot-outline and good references