My personal rules for country counting (my total is “only” 52): You must leave the airport and go through immigration. (The immigration requirement suspended for cruise ports because they usually don’t require each person to clear). And the country must be independent, not a possession or territory. So none of the islands on my French Polynesia cruise counted. And only a few (St.Lucia,Barbados,Dominica) on my 9-port Caribbean cruise. My 1984 refueling stop in Cape Verde doesn’t count - I got off the plane but didn’t leave airport property. And my trip to Antarctica counts as a continent but not a country - because it isn’t one. An interesting question came up in my family of country counters - what if it’s not a separate country now, but was when it was visited - specifically East Germany? (We decided it counts.)

Yes, East Germany counts, but maybe a trip to Yugoslavio in the 80s doesn't count towards all the countries its broken into now?

This debate has been had ad naseum inside and outide the serious country counting community. Most of us who've been to "every country" subscribe to the 193 UN members + 2-5 others. Why others? Most commonly accepted is Vatican City - who could join the UN but chooses not to. Everyone agrees. Next most agreed upon is Kosovo, who's recognized by way over half the UN member states, but due to Russia/Serbia vetos is unable to join. So that gets you 195. Lots of people also add Palestine, which is also recognized by over half the UN - but that's a discussion I think we should avoid. So, that's the 196 I use. Lots of others add Taiwan as 197. however, it has extremely limited UN recognition.

So...pick a list. Your list. TCC, Guinness, UN. MTP, NomadMania....there's no right or wrong answer...but I guarantee once you "hit them all" you'll look for a list of autonomous places to go after so that you still have something to chase...

I have been to Taiwan fwiw :-)
And Vatican