Angel (season 1)
At the end of the third season of "Buffy", the 242-year-old, re-ensouled vampire Angel left Sunnydale to give teenage Slayer Buffy Summers the chance to live a normal life. Angel is now living in the big city of Los Angeles. With Buffy gone Angel is now completely cut off from society, every day getting closer and closer to giving in to his vampiric hunger. It's not until he befriends the half demon and fellow Irishman Doyle, who is sent visions of people in trouble by The Powers That Be, and fellow Sunnydale resident Cordelia Chase, who grounds Angel's life in the humanity around him, that he truly begins to take charge of his life and seek atonement for his past sins. He sets up his own detective agency, Angel Investigations and begins to "help the helpless".
Viva Las Buffy!
Also, the writers, Scott Lobdell, Fabian Nicieza, and Paul Lee made a strong effort to offer a non-contradictory continuity which fills the gap between the events of Buffy burning down her school gym (seen in "The Origin"), and "Welcome To The Hellmouth". Though, being published before the end of the television series Angel (1999 TV series), "Viva Las Buffy!" directly contradicts the fact that in the episode "Why We Fight," Angel states that the only human he's ever sired while having a soul was Sam Lawson (in Viva they write Angel having also sired their original character Garner Siddle). In the Angel (1999 TV series) episode "The House Always Wins," Angel indicates that it has “been a while” since he’s been to Vegas. Saying that there “used to be dunes over there,” and further explaining that Bugsy Segal called them bug piles which means it couldn't have been later than 1947 since he’s been in town.