Why?

Because of the interactive remote controller.

This truly exceptional innovation sets the Nintendo Wii apart from all its competition.

Want to swing a club or sword - no problem just swing the wii remote.
How about hitting a ball - no problem just use the remote as a bat.

Just make sure you have plenty of room to move!.

This is the only console where you do NOT just sit down - you experience the game physically making any game you play a totally new experience and its much better for you as you don't spend hours just sitting in front of a TV.

The Wii remote uses radio technology to communicate with the console so there are no wires to get in the way and you can add several wii remotes to play multiplayer games e.g. fancy a game of tennis?

In adventure games you swing clubs, direct arrows to their target. For simulations e.g. a tennis game you control when and how you hit the ball. For aircraft simulation just roll the remote the direct the plane.

What's the Problem?

One of the worst things about the Nintendo Wii is that they are in short supply.

If you're having trouble finding a Nintendo Wii locally the best way of getting one is to use online shops.

As well as the standard online shops here are some resources that you may not have thought of:

ebay - There are many nintendo wii avaliable (there are up 1000 avaliable every day!).
amazon - They don't only sell books and they deliver anywhere

The advantage of using these resources is that they deliver anywhere and with ebay you may find a really good deal e.g. there are many systems bundled with lots of games at great prices.