Buffy the Vampire Slayer gets its fair share of credit for changing the face of feminist television, but its spin-off, Angel, deserves its own accolades for its thoughtful takes on morality, atonement, and soldiering on in the face of impossible odds.

After three seasons of romancing Buffy Summers (Sarah Michelle Gellar), and occasionally trying to kill her, Angel (David Boreanaz) decided to hit the road and head to Los Angeles in search of redemption. The resulting series was a wild ride with a slightly more cynical tone than the flagship. It also featured a pretty incredible ensemble that sucked fans in right from the get-go. Looking back on his time on Angel, which celebrated its 20th anniversary on Oct. 5, Boreanaz told TV Guide on the set of his CBS drama SEAL Team that the spin-off's ability to explore more mature themes was one of the things he loved most about launching his own series.

"That show, I thought, was really the adult version of Buffy and what that world was," Boreanaz said. "We explored some darker things."

When looking back on his favorite moments from the series, Boreanaz pointed to getting to work with Glenn Quinn, who played the half-demon Doyle until the character's death in the ninth episode of Season 1. (Quinn died of an overdose a few years later, in 2002.) "The best moment for me was really the pilot," Boreanaz said. "Working with my dear friend who passed away, Glenn Quinn, is still is a huge memory in my heart."

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Boreanaz added that watching the show develop over the course of its five seasons, particularly when it came to the stunt work, was also something he'll always cherish. "We shot on every rooftop pretty much and every alley, I think, in the Los Angeles area. I covered a lot of ground... Who could say that they rode a black horse [down a] downtown street with a lance? I was like, 'What am I doing?' So that was pretty crazy," he recalled, referencing Angel's memorable Season 2 premiere.

It doesn't feel like it's possible that 20 years have gone by since this beloved show premiered, but after listening to Boreanaz wax nostalgic about Angel's early days, we're definitely tempted to go back and binge the series about a vampire with a soul in all its noir, demon-fighting glory.

Angel is currently streaming on Hulu.

Additional reporting by Kelsey Pfeifer

Charisma Carpenter, David Boreanaz, and Glenn Quinn, Angel