Angel the Series
At the end of the third season of Buffy the Vampire Slayer, David Boreanaz's character Angel, the hunky, brooding, vampire with a soul, left the town of Sunnydale, California, and the television show that took place in that mystical locale. Since, at the time, the WB was being kept alive by Buffy, the network was quite willing to give that show's creator, Joss Whedon, a second show on the network, a spinoff from the original goldmine.
Thus, Angel the Series was born.
In this show, Angel, with help from various friends and sidekicks, fights the forces of evil in the demon-infested city of Los Angeles. Aimed at a somewhat more adult audience than Buffy, it began its life as a detective show of sorts, with supernatural enemies, almost like The X-Files. Quickly, however, it manifested itself as a story-driven genre show, with season-length overarching storylines similar to those of its parent show. The show also maintains the humor, fine writing, and personable characters (as well as the strange lingo) of Buffy, lending the show a following bordering on obsession.
Recently, after five years of incredible television, the show aired its last episode, Not Fade Away. The ending was sudden, surprising, and strangely satisfying. R.I.P.
Angel (David Boreanaz)
Cursed by gypsies with a soul nearly 100 years ago, he's doing penance for his centuries of evil, atoning for his sin. For now, his atonement is taking place in Los Angeles, where he fights all things evil. He runs Angel Investigations whose motto is "We Help the Helpless."
Doyle (Glenn Quinn)
A half-demon prophet of sorts who gets visions from the Powers That Be, he is sent to LA to help find his place. Under his guidance, Angel forms Angel Investigations, discovers the power behind the evil of the city, and joins up with Cordelia.
Cordelia Chase (Charisma Carpenter)
Another character brought over from Buffy, Cordelia was the biggest snob in Sunnydale, a spoiled brat. During her senior year at Sunnydale High, however, her father lost all of his money in an income-tax scandal, and she was left penniless. After graduation, she (unable to afford college) moved to Los Angeles to try to break into the acting world, only to run into Angel and join his new agency in a secretarial position. Her maturation from self-absorbed pain-in-the-neck to serious force for good is one of the most interesting side-stories of the show.
Wesley Wyndham-Price (Alexis Denisof)
A former member of the Watcher's Council (like Rupert Giles from Buffy), Wesley enters the show as an incompetent, arrogant "rogue demon-hunter," barely able to walk up stairs, much less fight demons. Under the guidance of Angel, however, he develops quite a lot as a fighter. More importantly, his scholarly background leads to him being a fantastic researcher, as he can read hundreds of demon tongues. Often, it is only his knowledge that tells the gang what to fight, and where to fight it.
Charles Gunn (J. August Richards)
A strong, uneducated young black man who lives in the bad part of town, Gunn leads a crew, almost a gang, against the vampire menace in his neighborhood. Reluctantly joining with Angel on an important mission (even after losing his sister to vampires), he is impressed by his power and agrees to help him on subsequent cases, eventually becoming a trusted member of Angel's team.
Lorne (Andy Hallet)
Originally known only as "The Host," he runs Ceritas, a demon karaoke-bar that is a sanctuary from violence. More importantly, when his customers sing, Lorne is able to read their futures and help them along their path. Eventually, he gets tangled up in Angel's investigations and, his bar being destroyed, joins with Angel permanently.
Winifred Burkle (Amy Acker)
Called Fred, Angel first meets her in another dimension, where she has been forced to live as a slave for the last five years after accidentally being transported there from the Los Angeles public library. Angel rescues her from that place and gives her a place to stay while she slowly recovers from the trauma of that experience. Upon recovering, it becomes clear that Fred is a genius at physics and, by extension, the scientific aspects of mystical studies - areas that Wesley's more historical leanings have left bare in the team's research. Therefore, she stays with the group and does her own part in the fight against evil.
Connor (Vincent Kartheiser)
Connor should not exist. A child conceived by Angel with another vampire, he is completely, so far as anybody can tell, human. He spends about three episodes as a cute little baby, before various unfortunate events take him away from his father, only to magically reappear a few days later as a sixteen or seventeen-year-old young man. Raised by Angel's enemy with a hatred for his natural father, he sets out to kill him, and nearly succeeds several times, only to slowly learn to respect him and fight by his side - sometimes.
Spike (James Marsters)
After dying saving the world in the last episode of Buffy, this other vampire-with-a-soul magically reappears in Angel's office. Temporarily bound to Angel's location, he learns to like working in LA, so that when he is released from the binding, he doesn't leave. Spike and Angel never got along very well when they were both evil, and they don't get along very well now either - especially since both of them are (or have been) in love with Buffy Summers. Still, they are both champions, and will fight shoulder-to-shoulder against the forces of evil.
Illyria (Amy Acker)
An ancient demon, Illyria infects the body of Fred midway through Season Five, taking it over completely. Confused by the twenty-first century, she attaches to Wesley in order to assimilate herself a little better into the society she has entered. Her character had little time to develop before the end of the series, unfortunately, but hope remains for later appearances of this fascinating creature.
Wolfram and Hart (Various)
Not really a character so much as an organization, this law firm appears to be the earthly front for a trans-dimensional evil group. Their motives are often unclear - Angel is their enemy, but they often appear to deliberately want him to stay alive, and the reasons for that are never quite known. The concept of a continuous organized enemy, a force of evil that lasts throughout the five seasons of the show, is one completely unique to Angel (that is, it didn't exist in Buffy) and it adds a pleasant constancy to the conflict.
Buffy the Vampire Slayer is my favorite television show of all time, but in many ways I respect Angel more. This makes sense - I am still of the age where I have the mind of a young adult, which this show is designed to please, but the instincts of a teenager, the intended audience of Buffy. I think that both of these shows are light-years ahead of most television in writing, combining amazingly clever dialogue with fascinating stories and characters. If Buffy is a little too silly for your taste - try Angel. It was designed for you. If you adored Buffy, also try Angel - it maintains much of the magic of the former show, and adds a good bit of its own.