Instead of listing the shows you like, why don't you tell us what type of shows you enjoy/are looking for, that would make things much easier.
Some suggestions to get you going:
NAME: Firefly (2002-2003) CANCELED [but there is a movie,
Serenity, which you can watch to tie some loose ends]
PLOT:Five hundred years in the future, a renegade crew aboard a small, spacecraft tries to survive as they travel the unknown parts of the galaxy and evade warring factions as well as authority agents out to get them.
TRAILER: click (couldn't find the official trailer or one that doesn't contain spoilers)
NAME: Game of Thrones (2011-) RUNNING
PLOT: Seven noble families fight for control of the mythical land of Westeros.
TRAILER: click
NAME: Breaking Bad (2008-) RUNNING
PLOT: Informed he has terminal cancer, an underachieving chemistry genius turned high school chemistry teacher turns to using his expertise in chemistry to provide a legacy for his family... by producing the world's highest quality crystal meth.
TRAILER: click
NAME: The Wire (2002-2008) FINISHED
PLOT: Baltimore drug scene, seen through the eyes of drug dealers, and law enforcement.
TRAILER: click
NAME: Carnivale (2003-2005) CANCELED
PLOT: During the Great Depression, an Oklahoma farm boy and a charismatic minister learn that they are key players in a proxy war being fought between Heaven and Hell.
TRAILER: click
NAME: Boardwalk Empire (2010-) RUNNING
PLOT: Chronicles the life and times of Nucky Thompson, the undisputed ruler of Atlantic City, who was equal parts politician and gangster.
TRAILER: click
NAME: Justified (2010-) RUNNING
PLOT: Old-school U.S. Marshal Raylan Givens is reassigned from Miami to his childhood home in the poor, rural coal-mining towns in Eastern Kentucky.
TRAILER: click
NAME: Twin Peaks (1990-1991) FINISHED [There is a movie (prequel) you can watch afterwards,
Twin Peaks: Fire Walk With Me.]
PLOT:An idiosyncratic FBI Agent investigates the murder of a young woman in the even more idiosyncratic town of Twin Peaks.
TRAILER: click [the quality of the trailer sucks, the show is amazing though]
NAME: Mad Men (2007-) RUNNING
PLOT: A drama about one of New York's most prestigious ad agencies at the beginning of the 1960s, focusing on one of the firm's most mysterious but extremely talented ad executives, Donald Draper.
TRAILER: click
NAME: Six Feet Under (2001-2005) FINISHED [Michael C. Hall, the guy who plays Dexter, is in this show]
PLOT: A drama series that takes a darkly comical look at members of a dysfunctional California family that runs an independent funeral home.
TRAILER: click
NAME: Oz (1997-2003) FINISHED
PLOT: A series chronicling the daily activities of an unusual prison facility and its criminal inhabitants.
TRAILER: couldn't find a good one, sorry. The show is great though.
NAME: Battlestar Galactica (2004-2009) FINISHED
PLOT: After losing the war against the Cylon robots, the Battlestar Galactica crew speed toward the fabled 13th colony, Earth. Galactica Commander Adama and President Laura Roslin face waning supplies, crushed morale, ... and the credible threat Cylons aboard the ship.
TRAILER: click
NAME: Freaks and Geeks (1999-2000) CANCELED
PLOT: A television show about two unique groups of teenagers dealing with life in high school during the 80's.
TRAILER: click
NAME: The Sopranos (1999-2007) FINISHED
PLOT: Modern day morality tale about New Jersey mob boss Tony Soprano, as he deals with personal and professional issues in his home and business life.
TRAILER: click
NAME: Castle (2009-) RUNNING
PLOT: After a serial killer imitates the plots of his novels, successful mystery novelist Richard "Rick" Castle gets permission from the Mayor of New York City to tag along with an NYPD homicide investigation team for research purposes.
TRAILER: click
That's it for now. I hope you find something you like. If you post exactly what you are looking for I can give you more specific suggestions. (list what you like about a show, the genre, comedy or more serious etc.)