I never think I have too many tanks, but my wife sure does! She also thinks that my constantly evolving ideas on what to do next with each tank. I had four tanks up and going, all freshwater, but we recently moved into our first house, which set me up for keeping saltwater, and so I went "way too big!" (wife's own words) with a 90 gallon bowfront. Right now I am down to two tanks (one salty, one fresh with cichlids) and I am right now staring at a new 10 gallon that I bought today and am cloning as we speak from my freshwater 55 gallon.
At the LFS today, while looking at some saltwater stocking options, I saw a really great planted tank and this has got me thinking. I just have to let the wife settle down a little before I bring that one up to her! I may have to go with tolak's plan and just have a fishtank room all to myself. To be honest, I have found that I can barely sleep unless I can hear the faint sounds of water dripping and air pumps humming!