I suppose, more so with states than countries, it depends on how long counts as "visiting". I wouldn't put down somewhere where I'd just used the airport to make a connection or one where I'd only driven through a small part of it without stopping, whereas others might count that. Making an overnight stay or visiting a specific attraction/event there would probably be my qualifier as to whether I'd list it or not.
On that note: (in order of visit, to the best of my recollection)
Countries - England, Wales, France, Spain, USA, Australia, Scotland, Canada, Czechia, Germany, Japan, South Africa.
US States - New York, California, Nevada, Arizona*, Hawaii, Washington, Colorado, Florida, Texas, Alaska, North Carolina*, South Carolina
Canadian Provinces - British Columbia, Ontario, Quebec, New Brunswick, Prince Edward Island*, Nova Scotia
* - day trips from other states/provinces, but I did spend a decent amount of time in them, wasn't just passing through