The downside to TV shows is having to make the decision between tagging in air-date sequence or production sequence. I’ve found it common that episodes produced in a particular sequence are not aired in that sequence. There are probably many reasons why the show creators did this, but you must make a decision so that you can enjoy the episodes in a way that makes sense, if any continuity is to be maintained. Here are some examples:
The Venture Bros, Season 1. The DVDs presented the episodes in production sequence. Bad move. Three episodes from the end of the sequence, an event profoundly changes the show so that the final two episodes no longer make sense. I won’t spoil this for those who haven’t seen it, but I suggest you look up the air-date sequence on Wikipedia and watch it that way. I was pissed when this happened to me, but I didn’t know ahead of time. In this case, definitely tag them so that they appear in air-date sequence.
SpongeBob SquarePants, Season 2: The episodes appear on the DVDs in production sequence, but they were aired in a different sequence. There seems to be no good reason for this, particularly since the first season’s episodes’ production sequence is the same as they one in which they aired. In this case, I chose air-date sequence, but you could go either way. As each episode is an isolated story, you won’t ruin any continuity.
Blackadder, Series 2: Air-date sequence has episodes 1 & 2 reversed. It also violates continuity as a result, so I tagged them in production sequence.
The Weird Al Show: Production sequence was thrown out the window. When I listened to the commentary, it was clear that the air-date sequence was out of his control, and that’s the way viewers saw the episodes, so I chose the air-date sequence.
Family Guy: This is the worst organised set of TV seasons I’ve seen on DVD. In Australia, we’ve just had “Season 6” released, but in the US, it was season 5. Also, three episodes are missing from the end of the season. This pattern started early on with these DVDs with the result that each DVD since season 3 actually represents the season earlier than it’s labelled. It’s a mess. The only clear choice was to put them in US air-date sequence and ignore the labelling.
My primary source of both air dates and production numbers is Wikipedia. I have found this to be relatively trustworthy. I also confirm when possible on the TV shows’ official sites.