None for cooking
None of these oils are healthy to cook with! most corn & canola oil is genetically modified so i would avoid if not organic.
Sunflower is healthy raw. For cooking best choices are olive oil (for low heat- under 350 degrees) and coconut oil for higher heat. See http://integrativemed.Kumc.Edu/school-of-medicine/integrative-medicine/health-topics/healthy-cooking-oils.Html for more information.