I've not read any Nicci French, but I have picked up a few of their books and thought I want to give them a try. Not sure my want to get list can take the strain though!
There are a few other Tess Gerritsens you've not listed; Call After Midnight, Under The Knife, Whistleblower, Never Say Die, Presumed Guilty, In Their Footsteps...and I think there might be a few more, although they're actually classed as 'romantic suspense', not a genre I'd normally go for to be honest, but I've read a couple of them, and they're really good, so might be worth a look.