Ooh, ooh! My turn.
The northernmost place* I've been in the world is the
Sognefjord in Norway. In North America,
Edmonton, Alberta.
The southernmost place I've been in the world is
Davis, California. In Europe,
Provence, France.
The easternmost place I've been in the world is
Serbia (either Belgrade or somewhere on the way to or from Čačak). In North America,
Cape Spear, Newfoundland -- as far east as you can go!**
The westernmost place I've been in the world is
Tofino, British Columbia. In Europe,
London, England.
* on land; my recent flight from Frankfurt to Vancouver took me over Greenland and the high Canadian arctic.
** unless Greenland counts.