This is not a Guide to show you how to find good domain names and avoid bad ones.
These are Domain names which you should really NEVER EVER buy or register unless you really like legal actions against you and problems.

• Do not buy, sell or register domain names which are or contain names of famous people like celebrities, politicians, etc.
• Do not buy, sell or register domain names which are or contain copyrighted trademarks like microsoft, intel, pentium, coke, etc.
• Do not buy, sell or register domain names which are or contain Typos of famous companies/organisations/websites, like yehoo instead of yahoo or mikrosoft instead of microsoft, etc.

Also on Ebay you always find people who offer such names and others who buy those names.
Those people are either new in domain name business and simply not aware of how dangerous such behaviour can be, or they simply don't care as they have no principles and/or are living in countries where they are no strict rules and laws. But even in such cases, violated companies/persons can take those names away from them by filing a complaint (Google for UDRP) and/or by lawsuits.

Keep your domain name portfolio clean and avoid such names.