not necessarily, would you say german/spanish league is better than serie a?
I don't often watch either, but whatever the answer is, I'd guess they're pretty close. And Italy only recently lost that 1 spot and mostly because of EL performances i.e. not because of the strength of the top teams.
Are there any interesting or strong leagues with only 1 strong team in them?
Trust me, I want inter, Milan and Napoli to fail as much as possible but I do not want to watch a boring league and one where I have to watch from a small screen on a laptop. The 2 are probably not exclusive, so I'd take the tears of the scum if I had to choose.