I would like to think that it's Sara Peretsky. However, there so many others that could hold that title. She is my choice for now. And the runner up would be, in my opinion, Janet Evanovich. Following closely behind her would be Sue Grafton. I have read them all and others. Sara came out on top for me. I will always think that all the mentioned authors above and many unknown others are really exceptional writers in their own right.
Agatha Christie is still best known. I'd have thought P.D. James is second. Val McD. (as mentioned) is magnificent; she should be much better known. And Harley Jane Kozak is a writer you have-have-have-to get to know.
Val McDermid is no. 1 for me, but hovering right up there is Minette Walters. I also love Carol O'Connell, even though she's a little off-kilter she's brilliant. Her book about magicians was wonderful, sorry I foget the title.
Shell Game. I am a huge O'Connell fan. Have all her first editions and I am always the first one there at B&N to pick up my copy the day they are due. I once made the manager go in the back and bust a box open to get one for me. It was the day it was SUPPOSED to be out and I wasn't driving back from the mountains, 50 miles in to Denver, a second time. I think I scared him!
I loved Mallory's Oracle, Stone Angel and Crime School and was over-awed by Judas Child.
I love how you keep us from getting too stuck in American/UK writers only mindset. I've got several new (to me) names on my must-check-out list from your posts. Thanks!
And... if you can get hold of Kerry Greenwood's new series set in modern times with Corinna Chapman, you will laugh out loud all the time. Adore this new series (well, didn't like the second, Devil's Food, but the others are brilliant). Kathryn Fox I think is doing really good stuff too as is P D Martin (she's actually from the same suburb as I live in).