Sue Grafton's Kinsey Millhone series: had read this once before, up to whatever was current at the time (O is for Outlaw?). Currently ready to start the last book so far, T is for Trespass.
Marcia Muller's Sharon McCone series: Also had read before, up to whatever was current at the time. I'm currently up to "Both Ends of the Night", or 17 books down, 10 to go.
Sara Paretsky's V I Warshawski series. Probably only four or five books in the series when I last read it. I'm now up to # 10 (Hard Time) of 13.
Robert B. Parker's Spenser series: Hadn't ever read it before. Wasn't much moved by the tv series, but really got into it with the made for tv movies with Joe Mantegna. I'm up to "Walking Shadow", which is # 21 of 35.
Michael Jecks' Simon Puttock series: I think that had three or four books, if that many, when last I encountered it. I'm on the second of 24 now (The Merchant's Partner).
And as mentioned before here, Piers Anthony's Xanth series: have read the first book, ready for the second (The Source of Magic), 30 to go beyond that.