Before he was the well-coiffed “Hardest-Working Man In Hollywood,” radio and television personality Ryan Seacrest was showing off his knack for hosting with a cameo appearance on Everyone’s Favorite Classic Young Adult Soap — Beverly Hills, 90210.

As TV Fans everywhere celebrate 90210 Day (9-02-10) and the tight-knit group of West Beverly students that were Brandon, Brenda, Kelly, Steve, Dylan, David & Donna, we mustn’t forget the celebrities who made some of their first television appearances on the series. Before they were big bankable stars, everyone from Jessica Alba to Hilary Swank and Matthew Perry snagged roles on the 90′s drama.

What’s your favorite episode of Beverly Hills, 90210? Post a clip!