It depends on the context. When combined with other subjective pronouns to form the subject of a verb, "I" is correct (as in "You and I are commenting on this topic"). However, when combined with other objective pronouns to form the object of a verb/preposition, you should use "me" (as in "Others are commenting on this topic along with you and me").[1]
[1] http://oxforddictionaries.com/us/words/i-or-me