I share Keen's opinion of the current answers, however, in concept it's a perfectly valid question ("which of the episodes of a show constitute a specific story arc") not nearly worthy of VTCing and perfectly on-topic and in-scope.
If you feel that the answer is trivial to obtain (not being an SME, I don't see how it would be), you can and should:
(1) Post the correct answer - as Izkata stated, a link to existing resource would be a good format.
(2) Down-vote the question for not doing obvious research, ...
(2b) ... ideally with a comment explaining to noobs like me JUST what you did to research it as learning aid.
 - IMHO, we have enough rep whores on SFF.SE that if it was, indeed, trivially answerable, we would more likely than not have already seen a good correct answer. The fact that one is missing leads me to be slightly skeptical of your assessment concerning the simplicity of answering it