Second best, and a distant second it is, would be governing a major state. I think being mayor of a major city would be close, but the voters, or possibly the parties, don't seem to think so. Maybe the lack of significant agriculture in cities is the deal-killer.
After that, we have being in the legislature. This strikes me as really different--you just don't make decisions on as large a scale, though you learn a lot about how things work and make a lot of contacts. Being first lady strikes me as falling into the knowledge/contacts category, and trying to get a health care plan through is definitely political experience.
Being a general is political experience of a sort, but I don't have a feeling for how it compares to being in the government.
Anyway, of the presidents consider the best, how much experience did they have? What about the worst presidents?
Addendum:Thanks for the answers.
There was a typo-- I meant to ask about the presidents you consider best and worst, but left the "you" out.