I can definitely vouch for Leeza Gibbons as tri-delt (she went to my school) and I always thought that Tiffany Amber-Thiesson and Delta Burke WERE ZTA's...
Anyway, here's the DG list:
Patricia Heaton
Julia Louis-Dreyfus
Christine Lahti
Joan Lunden
Donna Mills
Holly Shand (Road Rules)
Julia Sweeney
Well, I'm tired of typing, but here's the site:
http://www.deltagamma-msu.com/alumni.html