One has to wonder what counts as a "country," and when you can say you've done them all:

  As for least favorite, well, I was served goat in Somaliland
  in a situation where it was difficult to decline.

As far as I know, Somaliland is a bit of a 'limbo' state, it isn't universally recognised and many see it as just a region of Somalia.

If he visits Somaliland and counts that, did he also visit Transnistria? And if so, how low down the list do you go - do you then have to visit every self-declared nation-state all the way down to Sealand?

The list that fascinates me is the amateur radio DXCC list of "entities" which count separately. Many of them are dependencies of other countries, a lot are uninhabited (I might book my next holiday on Peter I Island or Scarborough Reef) but there are currently 340 of them: http://www.arrl.org/country-lists-prefixes

It's all really interesting stuff!