I definitely read TLCC before CL. I also just like Christopher better, for some reason, though I couldn't put my finger on why. It might have something to do with the latter portion of the book, after Gabriel gets blown into pieces. Cat gets to protag fairly heroically at the end, but he doesn't get to run things in the same way; once he frees Chrestomanci, the adults take care of a lot of the threat for him.

(I also love Millie. And Tacroy. And Throgmorton -- OMG, love on Throgmorton.)