In reply to sebastien:
As others have said/implied it depends how many features you want.
There are other makes, but the Garmin range is pretty comprehensive, and on the whole works really well.
Everything from the pretty basic FR10 up to the FR620 ( which will tell you your average oscillation height, ground contact time per stride, cadence, etc, etc ).
For a good middle of the range watch, with a bit of customisation, then the 220 is probably all you need.
Handtec.co.uk are normally cheapest, unless you have any discount codes for other stores. eg use MAY145 at sportsshoes today only for a further 10% off their already discounted price.