In ten years of consistant travelling, the best experiences I've had are:

1) Haggling in the night market in Kuala Lampur. If you go, stay at the Sunway Lagoon Resort Hotel.
2) Eating in 'the Dark restaurant' in Berlin, a pitch black restaurant where you dont know the specifics of your order and blind servers teach you to eat without using your sight.
3) All of Japan. The Japanese were fantastic hosts each of the five times I've gone there. I highly recommend memorizing a couple of key phrases (arigato) as they definately appreciate the effort.
4) Superbowl in Vegas. I'm not ever a football fan, but it wa frenzied in a really good way
5) The beaches in Nice, France
6) Mountain climbing in the Negev. There are peaks from which you can see seven different nations.
7) Bourbon Street on Halloween:/

#1 most overrated:

Amsterdam - It was great my first time, but prices have muliplied by four times since as compared to the US Dollar.