1 of 13 Justin Stephens/The CW, Everett Collection
Shenae Grimes, Shannen Doherty
2 of 13 Patrick Ecclesine/The CW
02-90210jessica-walter2
THE GRANDMANow: Tabitha Wilson (Jessica Walter) is a feisty granny who likes her drink. Her son and his family move to Beverly Hills to keep an eye on her.Then: Boozy grandmas were too controversial in the '90s, even for Fox.
3 of 13 Justin Stephens/The CW, Everett Collection
03-90210-steger-carteris1
THE BRAINNow: Savvy Navid (Michael Steger) produces West Bev's daily newscast.Then: Neurotic overachiever Andrea (Gabrielle Carteris) ran the West Beverly Blaze with an iron fist.
4 of 13 Everett Collection
04-90210joe-e-tata1
THE "NAT"Now: The CW had to bring the former owner of the Peach Pit back, but is it as the proprietor of the new kids' hangoutThen: Nat (Joe E. Tata) knew more about the gang than their own parents.
5 of 13 Justin Stephens/The CW, Everett Collection
05-90210estes-eckhouse1
THE DADNow: Harry Wilson (Rob Estes) conveniently takes over as the principal of West Beverly High School.Then: Jim Walsh (James Eckhouse) was a sucessful financier, proud papa and an ever-so-sharp dresser.
6 of 13 Justin Stephens/The CW
10-90210jennie-garth2
THE COUNSELORNow: No longer an impressionable bad girl, Kelly Taylor (Jennie Garth) will advise the new kids.Then: Those kids could have used a guidance counselor - so many issues!
7 of 13 Justin Stephens/The CW, Everett Collection
08-90210priestley-wild1
THE GOLDEN BOYNow: Despite his lack of sideburnage, Annie's adopted bro Dixon is a star athlete and scholar. Then: There was nothing Brandon did that didn't work out in his favor.
8 of 13 Justin Stephens/The CW, Everett Collection
07-90210garth-mccord2
THE BAD GIRLNow: Naomi (AnnaLynne McCord) doesn't like to lose, especially her boyfriend to the new girlThen: Kelly Taylor (Jennie Garth) started out as a real megabitch, but the years mellowed the Queen Bee into something more nurturing
9 of 13 Justin Stephens/The CW, Everett Collection
09-90210milligan-ziering1
THE LIFE OF THE PARTYNow: Ethan Ward (Justin Milligan), the Big Man on Campus, has laser-focused sexy eyes for AnnieThen: Steve Sanders (Ian Ziering) had quite the stare as well, though he was mostly looking at beer.
10 of 13 Mark Mainz/Getty Images for TV Guide Channel Studios
10-90210-tori-spelling1
THE WACKY BEST FRIENDNow: Well, stay tuned. Spelling was set to reprise the role of Donna, but talks with the CW stalled, reportedly over pay.Then: Donna Martin was the sweet virgin whose awkwardness was mostly played for laughs.
11 of 13 Justin Stephens/The CW, Everett Collection
11-90210loughlin-potter1
THE MOMNow: Debbie Wilson (Lori Loughlin) is a modern mom whose Midwestern values will be tested in the wilds of California.Then: The smiley Cindy Walsh (Carol Potter) was motherhood incarnate.
12 of 13 Justin Stephens/The CW, Everett Collection
12-90210-eggold-perry2
THE HEARTTHROBNow: But wait, you say, he's the teacher! Will Mr. Matthews (Ryan Eggold) have an affair with a studentThen: Dylan (Luke Perry) snared the ladies with his laid-back surfer style and one hell of a James Dean whisper.
13 of 13 Justin Stephens/The CW, Everett Collection
13-90210-stroup-thiessen1
THE TROUBLEMAKERNow: The original baby Erin Silver (Jessica Stroup) - now known only by her surname -makes scandalous YouTube videos.Then: The vixen Valerie (Tiffani Amber Thiessen) filled the complicated brunet void left when Doherty departed.