Here is a list of most common passwords which are very easily hacked. Worldwide people tend to make the same mistake.
The list goes as :
The best passwords made are a nonlogical combination, that which cannot be guessed. Security experts suggest taking a sentence and transforming it into a non-existent word. For instance "This little piggy went to market" might become "tlpWENT2m". You should use a combination of words of upper and lower case with a special @, #, % symbols.