One of the greatest television shows of all time, David Simon's The Wire transcends the medium with its blend of gripping character drama and vital social commentary. The show's authenticity, complexity, and depth have led to universities offering courses on it, but unfortunately those attributes did not bring in big ratings. Despite the fact that the show featured few established actors, dozens of cast members (many of whom were amateurs) shine throughout the show's five seasons.

The most successful of any of HBO's original series, The Sopranos established the network as a major player in original programming. Despite HBO's limited viewer base, this show regularly drew bigger audiences than competing network programming and was a cultural sensation. It is rightfully viewed as one of the most groundbreaking television shows of all time and was the first cable series to win the Emmy for Outstanding Drama Series.

Unlike the top two entries on this list, Six Feet Under is a more personal and introspective drama and perhaps the television show to deal most heavily with the topic of death. Creator Alan Ball's excellent scripts are brought to life by an excellent ensemble cast that earned multiple Emmy nominations nearly every year of the show's five-season run.

This ten-part miniseries based on Stephen Ambrose's novel was executive produced by Hollywood heavyweights Steven Spielberg and Tom Hanks following their successful collaboration on Saving Private Ryan. The show - which had a record-breaking budget of $125 million - chronicles the trials of Easy Company, a parachute infantry regiment of the U.S. Army. The series was nominated for 19 Emmy awards, winning six, and also won a Golden Globe for best miniseries.

Created by Tom Fontana, who like David Simon previously worked on the excellent Homicide: Life on the Street, Oz is a gritty drama about life at the Oswald State Correctional Facility. The first one-hour drama produced by HBO, this show fully embraced the freedoms of premium cable and is chock full of male nudity, profanity, and shocking violence. While the show did not haul in the number of awards that other HBO dramas have captured, it maintains a dedicated following to this day.

Adapted from Tony Kushner's Tony- and Pulitzer Prize-winning play, Angels in America broke records at the time for most Emmys awarded to a program in a single year, with 11 wins on 21 nominations. The story, a political and personal tale about AIDS in the mid-1980s, is delivered by a star-studded cast featuring Meryl Streep, Al Pacino, Emma Thompson, and Mary-Louise Parker.

David Simon's six-part miniseries The Corner was the predecessor to The Wire. Both shows - which feature many of the same actors - focus on the impact of the drug trade in inner-city Baltimore and are riveting, yet bleak, tales of urban life and the drug trade. The show offers an intimate and bleak view of one family's struggle to avoid the cycle of addiction and violence. Directed by Charles S. Dutton, The Corner won three Emmys, including for best miniseries. It also proves that the former Roc star deserves more directorial opportunities.

Deadwood must have packed in more profanities per hour of programming than any show in the history of television. According to creator David Milch, who is also responsible for NYPD Blue, the anachronistic profanity was used because accurate period slang sounded ridiculous, and the lawlessness of the town - 1870s Deadwood, South Dakota - and the characters had to be conveyed. Despite a loyal following and critical praise, the show was canceled after three seasons.

With a strong ensemble cast, this epic series chronicles the lives of two common men, Lucius Vorenus and Titus Pullo, as they play a part in various historical events surrounding the rise of the Roman Empire. The series, developed under contract with the BBC, only lasted two seasons due to its massive budget and grand scope, though a film continuation has been rumored.

Examining the life of the chronically overlooked founding father and his role in the formation of the United States, John Adams is one of the finest productions of any kind dealing with revolutionary America. The seven-part miniseries is driven by the gripping performances of Paul Giamatti and Laura Linney as John and Abigail Adams; the pair swept the Emmys, Golden Globes, and SAG Awards for best actor and actress in a miniseries or TV movie. All told, the miniseries was nominated for 23 Emmys and beat Angels in America's record with 13 wins.

Although Big Love has taken a bit of a sideways turn after its excellent first two seasons, we still think it is one of HBO's better original series. Created by Mark V. Olsen and Will Scheffer, two relative newcomers to the world of television, this show examines the lives of the polygamous Henrickson family, led by its patriarch Bill, a home improvement store owner and political aspirant. But the more interesting portions of the plot involve the relationships between the Henrickson sister wives and the often sordid affairs of the characters' extended families.

Few shows have as fascinating a setup as Carnivàle. It follows a traveling carnival in the 1930s Dustbowl that includes a young man named Ben Hawkins, a psychic who can bring the dead back to life. His powers are mirrored in the sinister Brother Justin, a California preacher with a mysterious connection to Hawkins. The cinematography and art direction in this series are especially superb. Dwindling ratings caused the show's unfortunate cancelation after two seasons, leaving many of its mysteries unresolved.

While we are not the biggest fans of True Blood, the latest from Six Feet Under creator Alan Ball, it is undeniably stylish, sexy, and popular. The show loosely follows the adventures of a psychic girl named Sookie Stackhouse in a world where vampires have integrated into society. With this premise and other supernatural creatures such as shapeshifters, the show packs in plenty of violence, blood, and sex into every episode. What's most interesting about True Blood is its word-of-mouth success; it premiered with very low ratings which have gradually increased to the point that it has become HBO's second-most watched series, trailing only The Sopranos.