As a rule, we have to use the subject form of the noun after the verb "to be" (is in this case), but what if we have the following example?

Example: Who is important, you or me/I?

Here (http://www.daltonstate.edu/faculty/mnielsen/pronoun_case_1_key.htm) it says "you or me" is correct for the example they've given, but I'm not finding whether the general consensus is that "you or me" is always correct use.