Archery - I love this. The Wiimote and Nunchuk are used in such an innovative manner that I often forget they are pieces of wifi emitting plastic and metal. My only complaint would be that the bow can lean in some very odd directions sometimes!
Cycling - This results in severe Wiitis (look it up) after a couple of hours of play. It is highly addictive, even if you don' quite realise how you are supposed to pedal (like me)
Surfing - Highly addictive this is based on the simple theme of jumping and landing straight on the base of the board. In just over a minute youwill have clocked up hundreds of points!
There are many more sports I could mentions, but if you have a large family, and 179.99 doesn't sound too expensive, I would highly recommend investing in a Wii!