3. She Had The Physicality
I'm not talking about looks per se (those are pretty obvious). I'm talking about physical presence. Since the late 80s and continuing on with the current New 52 relaunch, the Lois of the comics is an army brat, her father, Sam Lane, being a General in the US Army. As such, Lois is supposed to be a fair hand-to-hand combatant who knows how to handle a weapon and isn't afraid of a fight. Durance, more than anyone prior, portrayed her as just such a person. Throughout her tenure, Durance/Lois got into more than her fair share of fistfights. In one episode, she claims to be a third degree black belt, and in another, shes arrested for allegedly paralyzing a college football player via kick to the groin (granted, it turned out the paralysis wasnt her fault, but she did knock him on his back with said kick). In another episode while Clark was de-powered and they were both trapped in a military compound, it was Lois who took the lead in trying to get them out alive, and she did it while armed. In short, Durance/Lois not only kicked way more butt than any previous or prior incarnation thus far, but all the while she looked believable doing it.