Let's get one thing straight right off the batt: Buffy the Vampire Slayer was an incredible, groundbreaking TV series and may have been the first time when a TV adaptation of a movie actually surpassed the original film. Joss Whedon's series of a teenage girl who is chosen to be the principle warrior against the forces of darkness managed to wow viewers week after week with incredible characters, great storytelling, and some of the best dialogue on TV at the time.
From the beginning of the series, one character really captured viewers' imaginations - Angel, the vampire who had been cursed with a soul to suffer for his violent actions. The tragic romance between Buffy and Angel has become legendary in the world of television. And following the third season, Whedon made the decision to break the couple up and give Angel his own spin-off.
Whenever a TV show spins off one of its popular characters, it's a risky move and it doesn't always go well. Even the best spin-offs never really reach the heights of the original series.
But Angel was the exception to the rule. While Buffy tended to flounder a bit after the third season and never really seemed to find its footing after leaving behind Sunnydale High School, Angel managed to be an amazing mix of drama, horror, characterization, and humor.