Check out Vimeo. You can find some really good shorts, reels, etc. there. Also, never put anything up on YouTube that you intend on entering in a Film Festival or for distribution in other ways. Some festivals don't accept films that have been put up in the public domain. And also putting things on YouTube gives you less protection against copyright so I would advise against putting up everything from completely original work as well -- even if you have it copyrighted.