I have developed expired domains database, at the beggining it was my private project, but I already have what I need so I've decided to share my database with other people. It's free, You don't have to log in or pay for access. It allowes You to browse domains by page rank, back links, alexa rank or previous content keywords. It's updated every day with around 1000 new checked domains. You'll have all the informations that allowes You to check if it was not previously a link farm or some other spam domain.