I think that
Airline safety and security information may be the best source as it appears to be rather more scientific and professional. Others are based on payments and amateur comments such as : "The coffee was good and the cabin crew were nice and I felt very safe."
Whereas we may well feel safer on Swiss than on Cubana, past performance is no indicator of safety, and flying is so safe that in real terms there is not much difference in your chances, in a normal year of flying, of having a prang on the best or the worst.
I have a friend who won't fly on certain carriers, which he feels are unsafe, when he flies from A to B, but he will travel on what he considers a safer carrier with a change of aircraft en route, meaning he has 4 take offs and 4 landings on a round trip, rather than 2 of each, thus almost doubling his chances of being involved in an incident, since the majority occur on the take off and landing phases.
Skytrax/Airlinequality.com is a joke.