my best friend has the s3is, I have a panasonic fz-28. He bought the panasonic for his gf when she needed a new camera, they looked at the sony, the s5is and the panasonic. There is a newer panasonic, the fz-35 if you want the most current, but that should lower the price on the fz-28.
We just liked the shots from the panasonic. The canon's menus were better, but we took our own sd and memory stick to abe's of maine and tried each camera. When we got home and looked at the shots, the panasonic consistently had a better shot, especially after small touch up. The canon had more vivid colors, but could not expose my daughter who is very pale. The sony exposed my daughter, but just didnt seem to have all the ability of the panasonic. the panasonic shoots flatter more realistic color, but you can push the color up in settings on the camera or just fix on the pc when doing crops.