Spin City is a show where every episode is different and funny and entertaining. I prefer Mike to Charlie, and i've seen most of the ones with Mike and only a few with Charlie. The characters on the show are all funny and are all very well represented. I don't think Caitlin ruined the show. I think she did a good job making the transition between Mike and Charlie. The later years were like a whole other show with most of the original cast gone, but Spin City really knew how to carry on with the show.
I think the show is underappreciated and i wish they played it in Canada.