I used to think this too but if all the recipe websites start going straight to the recipe without the the personalization, then how would you rank them? Remember, there are thousands of these websites while there are only so many ways you can boil an egg, for example.

PageRank-like system, ideally based on real identities? (i.e. depending on how often the recipe is linked from Facebook, etc.)

Also if you are specifically doing it for recipes, just select manually websites that have precise ingredient amounts, very detailed and explicit recipes, that explain the reasoning behind each step, provide photos of how things should and shouldn't look like, why the proposed technique is optimal and/or the tradeoff of alternative techniques, the chemistry involved, comparison with other recipes, etc. (although in my experience most or all recipe sites are horrible and aren't even vaguely close to something like this)