Sardines and Mackerel are my staple canned fish. Not a huge fan of the taste of sardines but they are super healthy, low mercury, and are fast breeders so it's harder to over fish them. Mackerel is my favourite canned fish period but can be a little expensive. The important thing to remember about canned fish though is it's origin. Try to avoid anything from Southeast Asia. The industry there has a terrible record of human right abuses.