Someone wishing to become familiar with ancient Greek tragedy has a simple task in at least one respect: there are only 31 surviving ancient Greek tragedies. Many more than these were written, but we know of them only from descriptions by other ancient writers, and here and there a small fragment, a few words, of an otherwise lost play.
It's even easier, remarkably easy, to gain an oversight of ancient Roman works written for the theatre -- works of all kinds, not just tragedies. From all eras of ancient Rome, the only plays to have survived, apart from a few fragments, are 10 tragedies by Seneca (and if you ask me you can go ahead and skip those anyway, and the rest of the surviving work of the intensely boring Seneca), and then one anonymous comedy from the 5th century AD, then six comedies by Terrence, and then 20 comedies by Plautus, plays about which 2 remarkable things may be observed: first, the great contrast they make to most ancient Roman literature which has survived down to our day, and second, how immensely popular they were in ancient Rome among writers who never even tried to write anything remotely similar to them.
It's a seeming paradox: how highly so many other ancient Roman authors praise Plautus, and how few write in a style comparable to his. For the most part Roman authors aimed for a very refined and polished style, which can make for very good reading, but which tells us very little about how ancient Latin was spoken on a daily basis. For those trying to recapture ancient spoken Latin, Plautus is always the first stop. He didn't aim for the usual polished refinement, he aimed to make audiences laugh, and he succeeded brilliantly at that, and when he died at the end of a long and fruitful career he was widely mourned -- but, as far as we can see from the evidence of surviving ancient Latin, he was very little imitated. Perhaps his remarkable popularity had to do in part with how unique he was in Roman culture -- so unique, perhaps, that his contemporaries would scarcely known how to have imitated him. It certainly doesn't seem to have occurred to many Romans to try to preserve the texts of plays in the same way that they preserved lyric poems and speeches and historical works. In Plautus' case, the effort at preservation became intense only some time after his death, collecting together copies of the plays which had been used, and often altered, by theatrical companies. It wasn't unusual in ancient Rome for written works to be falsely attributed to famous dead authors, but the extent of such confusion was unusual in Plautus' case: Varro tells us that over 120 plays were circulating under Plautus' name, and asserts that 20 of them are really from Plautus, the same 20 which are accepted as his today, plus a fragment several pages long of a 21st play accepted as genuine by Varro.
Plautus was not raised to be a scholar. This sets him apart from most of the Roman authors we know. Unlike most of them he was neither an aristocrat nor the slave of an aristocrat nor dependent upon the patronship of aristocrats. Details of his early life are very sketchy, but it seems that for a time he was a businessman, and that he lost all of his money, and then spent some time as a manual laborer in a mill before beginning his career as a playwright.
Just as aristocrats played relatively little role in Plautus making a living, so much fewer of his characters are from the ruling classes than is typically the case in Classical tales. His protagonists are merchants and laborers and slaves, and rather than being preoccupied with the destinies of nations and the will of the gods, they tend to have sex and money on the minds.
The soldier Pyrgopolynices, who is the title-character of Miles Gloriosus, is not a glorious warrier, but a vainglorious braggart, a ridiculous figure whose shield, in a pointedly disrespectful reference to Achilles' legendary shield, is a monstrously huge object which has to be dragged around by several servants at once and can obviously never actually be used in combat. Miles Gloriosus reflects a widespread weariness on the part of the Romans with war: when it first appeared, the Second Punic War had been going on for some time. Most Roman writing about that war glorifies it, a stark contrast to Plautus' satire of military pride. Instead of actually fighting, Pyrgopolynices spends most of his time bragging about battles he wasn't actually in, and trying to satisfy his lust and greed.
Plautus' play Menaechmi is the model for Shakespeare's Comedy of Errors, and its characters can be neatly divided into the honestly confused and the relentlessly dishonest.
For the most part Plautus in his plays strictly avoids the sort of moralizing and attempts at deep thought with which much Classical literature is rife; a partial exception to this can be seen in Asinaria, in which it is suggested that virtually every member of humanity is victimized in one way or another: women are perpetually dependent on men for money, men are slaves to their lusts, and then of course there are the many men and women who are literally slaves.
Plautus and Terrence, two writers of comedy very popular in their own time and since, are the two most prominent ancient Roman playwrights. Some people argue that the one or the other is the best Roman playwright. I think it's rather meaningless to dispute that question. Plautus and Terrence are apples and oranges. Terrence's writing has the polish and sophistication and the aristocratic orientation common to almost all of the ancient Latin literature we know. Plautus is special not because he's necessarily more brilliant, but just because he's so fundamentally unique. Unique among the surviving authors, that is. Who knows what the lost literature may have been like. Who knows how much will be found again and how much it will alter our overall perception of ancient Roman culture -- but until such a time, Plautus stands out among writers who tend toward stiffness and artificiality. Seen among most Latin authors of his time, he's somewhat like a man who's been invited by accident to a very, very formal ball, shows up with an entire cabinet's worth of cream pies, and proceeds at once unceremoniously to hurl them at every face within range.