Rockwell and fuckface are right.. 9 out of 10 times it is my friend and I for the reasons you cited. However, if you re-read the mangled post its just like your sentence b. You were alluding to quickly testing whether to use "and me" or "and I" in a sentence. Just take out the other pronouns and just make it about yourself. Once you create the sentence using you, THEN bring in other characters. Examples: I went to the store Becomes My friend and I went to the store After whistling, rover ran to me. Becomes After whistling, rover ran to my friend and me. We would never say 'me went to the store' or 'rover ran to I' Introducing more characters into the play doesn't allow us to change the rules. Agreed? Great. But what is ironic is that you did not do that on the sentence under current examination.