10 Reasons Angel Is Better Than Buffy
3. The Big Bad?
One of the characteristics of Buffy was the presence of the "Big Bad," a season-long villain who would lurk in the background, manipulating things from behind the scenes, before an inevitable confrontation with Buffy at the season's end.
Angel took an opposite move. Instead of each season having a separate Big Bad, Angel gave the entire series a Big Bad—the interdimensional law firm, Wolfram & Hart. Run by a trio of ancient demons, the Wolf, the Ram, and the Hart (known as the Senior Partners), the law firm defends the worst of the worst.
The use of Wolfram & Hart allowed for a lot of interesting concepts to be developed over the course of Angel's run. In the first season, Angel expresses frustration at the fact that he can't fight for mankind because Wolfram & Hart can use the laws to bend the rules in their favor.
One of the most chilling moments of the series came in the second season when Angel finds a way to Wolfram & Hart's Home Office. Thinking he's going to go to Hell, Angel is told by Holland Manners that Wolfram & Hart exists because of the evil within humanity, so he'll never be able to destroy them.
With Wolfram & Hart, Whedon created a villain Angel could never defeat, could never even punch.