the various sites that try to catalog Mac apps range from worthless to disappointing
It's not really a lot better for other OSes.
FWIW, I tend to use
IUseThis, which could really use a better tagging feature, and
AlternativeTo.
VersionTracker has always been lousy, and now that it's just CNet, it's even lousier. MacUpdate is lousier than old VT, but better than new VT, which is to say, lousy.
If someone has another suggestion, I'd like to hear about it.
Also, there's already an app called Bodega that is an App Store for OSX. I imagine they're thrilled at this news.