Why marathoning a show is not always a good idea

I watched most of the first season of the Big Bang Theory over the course of a couple of weeks.  I enjoyed the show, but I noticed something kind of odd.  In this marathon--and back when I marathoned Firefly--I began to suspect that episodic shows with multiple writers (most of them for weekly television series, I would imagine) tend to seem kind of scattered.  I didn't comb through scientifically, but there seems to be a pattern where certain episodes play up certain facets of certain characters, and I wonder if the episodes that play up the same thing are by the same writers.  I don't know if some writers just like certain characters or feel that certain sides of those characters don't get enough screen time, but the overall combination can seem oddly uneven when watched en masse.

I hesitate to say that this makes the whole seem artificial because by nature these things are artificial: they're TV shows about fictional people, but maybe this is why shows are still often played weekly: people don't nit-pick about this sort of thing when there's a whole week of life in between brief viewings of these fictional lives.

While Firefly was definitely more obvious in this regard, it's only fair to point out that it was also shorter in terms of episodes, so maybe the episodes that would have helped even things out never got made.

Are there any shows where you've noticed this disparity between character continuity in different episodes?  Do you care?