Well, you can all say more than five actors or actresses if you want to.
and you can also say guest stars. In that case, here's my list:
Top 5Maggie Geha (Gotham)
Kelly Hu (Arrow)
Amy Jackson (Supergirl)
Jessica Lucas (Gotham)
Italia Ricci (Supergirl)
Regular cast and recurring charactersOdette Annable (Supergirl)
Tala Ashe (Legends of Tomorrow)
Morena Baccarin (Gotham)
Violett Beane (The Flash)
Melissa Benoist (Supergirl)
Lynda Carter (Wonder Woman)
Katie Cassidy (Arrow)
Cassidy Freeman (Smallville)
Juliana Harkavy (Arrow)
Teri Hatcher (Lois & Clark)
Willa Holland (Arrow)
Minka Kelly (Titans)
Chyler Leigh (Supergirl)
Peyton List (Smallville and Gotham)
Allison Mack (Smallville)
Dina Meyer (Birds of Prey)
Julie Newmar (Batman (1966))
Danielle Panabaker (The Flash)
Candice Patton (The Flash)
Maisie Richardson-Sellers (Legends of Tomorrow)
Emily Bett Rickards (Arrow)
Ashley Scott (Birds of Prey)
Laura Vandervoort (Smallville)
Guest StarsAmy Adams (Smallville)
Brianna Brown (Smallville)
Joan Collins (Batman (1966))
Jessica de Gouw (Arrow)
Amy Gumenick (Arrow)
Amy Hathaway (Lois & Clark)
Marianna Hill (Batman (1966))
Pascale Hutton (Smallville)
Sherry Jackson (Batman (1966))
Jill St. John (Batman (1966))
Natalie Alyn Lind (Gotham)
Lori Loughlin (Birds of Prey)
Keri Lynn Pratt (Smallville)
Serinda Swan (Smallville)
Shantel VanSanten (The Flash)
And how about unaired pilots. If those count, then I'll add the following:
Unaired PilotsSherilyn Fenn (Birds of Prey)
Amber McDonald (Aquaman)
Daniella Wolters (Aquaman)