I just added up my rods and now have 11 with a lot of overlap in line weights but with different actions (I won 4 of them and built 2 very inexpensive ones) and have used all but one this year. Somehow I still feel like I have some holes in my arsenal. As I'm branching out into new areas, I'm thinking I would like some more specialized rods for bass, czech nymphing, and larger saltwater as well as a longer small rod for the many small rivers/fish we have around here.
Part of the trouble is learning what I like. I'm starting to get a feel for the various actions available and that will probably be the reason I'll get rid of some of the rods I now own.