lupei said:
-I am opposite you
-I am opposite of you
'I am opposite you' suggests location.
Perhaps:
'I am seated opposite you.'
-on opposites sides of a table, or across an auditorium on the opposite side.
'I am the opposite of you.'
-indicates polarized personality differences, or opposite opinions.
You like to stay awake late at night. I'm the opposite of you. I like to go to sleep early.