You should stick with extras and OVI store only. There isn't 'crap' there. The apps are free..and you're still complaining?
I think you are raising a very important topic, and the one that definitely requires community attention. Being an expert in software quality assurance, you should probably create your own repository for N900 software, only containing high-quality well-supported software titles hand-picked by yourself and other quality software experts. Once you do that, advertise your repository to all the N900 users eagerly awaiting such a repository. Happy New Year and good luck in your endeavors.