While I have not participated in the previous two seasons I will have a go now:
1. Faye Kellerman's Peter Decker and Rina Lazarus series (I only read book one, so this alone is a challenge) which could also be counted toward the Jewish Challenge I guess, but I will need to whole year to catch up
2. Elizabeth Peters' Amelia Peabody series (can only take a book at a time, but they are in my TBR pile)
Both of those series can count against my RYOB for quite a while as I have a couple of each to read in my shelves.