I think this is a very good idea. I made a similar suggestion in the Security WG proposal, regarding crates under the cryptography category. Though this more meant as a officially endorsed list, where listed crates had been reviewed, I think a community effort like this one could work in conjunction with the Security WG if they decide to implement my suggestion.
Or a community-wiki could be a starting point of something the Security WG could base their list off of, taking crates listed there and review further.