I see some of my favorites already on the list, but here are a few others.

Farscape: Aeryn Sun
Buffy Vampire Slayer: Buffy Summers, Faith (Can't think of her last.), Willow.
NCIS: Ziva David, Abbey (same about the last name)
Buck Rogers: Colonel Wilma Deering
Law Order SVU: Detective: Olivia Benson
Charmed: The charmed ones take your pick - Piper, Paige, Phoebe, and Prue.

And there are some female attorneys and detectives from some television shows I could list too.