Highest place I've been:
Nepal, 'bout 15 miles south of Everest Base Camp. Always wanted to go to Base Camp and woulda made it too had my companion not fallen ill with altitude sickness. I didn't know him that well and it was tempting to journey on alone but he was in a bad way and it was a 5 day trek back to Lukla and so I couldn't leave him. Just felt wrong. Sometimes you gotta not be an arsehole.
Lowest place:
Dead Sea. Came here a few times when I lived in Israel. Cool place, spookily still, and so silent it hums. Water hurts like hell when you get it in your eyes.
Most northerly:
Newfoundland, Canada
Most southerly:
Lagos, Nigeria. Crazy, dirty, ugly city. Beautiful country though.
Most westerly:
New York. Spent a year here. Didn't like it.
Most easterly:
New Delhi, India. I love India. It's an assault on the senses and murders any preconceptions you have regarding how the world should be. You might see the most beautiful thing you'll ever seen one moment, and the most distressing or disturbing thing you'll ever see the next. It's that kinda place.