From three reviews I found, when you check the noise levels for ISO setting in the "Image Quality" section, at ISO 1600 (100% Crop) both canon and panasonic are better than the sony. In the "sample Images", because they used different setting so they are hard to compare, and they look good for 3 of them. If you don't mind the camera size, get the canon sx50, and I will recommend to get the panasonic, also it's lens made by LEICA that is one of the most famous names in photography. Other function like GPS/wi-fi is only for sony and panasonic, that is nice function. And panasonic has a 3D Mode option too.
Canon http

/www.photographyblog.com/reviews/canon_powershot_sx50_hs_review/
Panasonic http

/www.photographyblog.com/reviews/panasonic_lumix_dmc_tz40_review/
Sony http

/www.photographyblog.com/reviews/sony_cybershot_dsc_hx50v_review/