WG-1 or WG-2
If I were choosing between the two, I'd get the WG-2 for the sensor. The newer model has a BSI-CMOS sensor which will give you considerably better low light (High ISO) image quality than the CCD sensor in the WG-1. This will make the camera more versatile.
I'm not an owner of either, but had been comparing them as a "tough" take everywhere compact.