I haven't seen more than a few episodes of The West Wing, but what caught my attention about this discussion was the issue of age and the concept of the "entry point character." I think it's easy to see where age might affect who one relates to within a canon (as well as one's viewpoint on many of them), but I also wonder if others have found their entry character ending up not being the one who keeps them in the fandom?
I was equally surprised by the fandom focus on Darcy, especially since I thought Jane was an interesting character. Despite her attraction to Thor, her main focus is her work and her scientific curiosity, and one could see her as fascinated with him even if he weren't, well, a Norse god.
I did like Darcy, I thought she and Jane were fun together. But it surprised me that a nerdy fandom didn't identify more with the science nerd (especially since Science Bros was soon to be a thing). And while many took the opportunity to pair Darcy with Loki (who was very clearly the more popular character), I always thought it would make more sense for Jane and Loki to find things in common. Yet there are relatively few Jane/Loki stories. What's more I often haven't seen Darcy used well in stories. After all we don't get to know her particularly well (and apparently never will given what's happened with Jane in the MCU) but there are some things about her that seem fairly fixed and I often find her written in ways that either do nothing to develop her (she just ends up being someone things happen to) or else she's developed in ways that seem quite inconsistent.
I've tried thinking about recent shows I've been watching and if there are any particular characters who draw me in. I find mostly that I can't dislike the main character or else I won't be able to keep watching, but I may prefer a different one. So, for Victoria it's varied depending on the season, for Good Fight it's Maia rather than Diane, and for Brooklyn 99 it is probably Captain Holt because I find him the funniest. Raymond and Kevin are hilarious together. And I guess he's not prickly so much as standoffish which probably makes him such a good contrast to many of the other characters. I like the way B99 pairs them all up differently from episode to episode, because that makes for the best character development. Holt with Rosa is different than Holt with Amy or Jake or Terry.
In Buffy my entry point was Giles, quite literally. I started watching Buffy after an American Libraries cover story with Giles. But I liked all the characters. I started watching in S4 so Spike was already there, but he also didn't become my main character until S5.
Overall I find it's the writing that draws me in more than particular characters, but then the last fandom where I was mostly interested in characters was Merlin.
In that, I grew to love the characters in spite of the show and Merlin was the entry point to that. However I found that by the end it was Arthur who was my favorite. (It might well have been Gwen, but the secondary characters were so poorly developed that I liked Gwen's potential more than what we actually got). I think it was because Arthur had both established himself as a good leader, as well as because he was, unknowingly, being ill done by so many people even as he tried to become a better person.
So overall it helps to draw me in if a character is humorous and is either very smart or very personable. So it's perhaps not surprising that in many fandoms this is not the lead character but a secondary character instead.
Are there particular characters who are always your entry point? Does it change over time? Does it depend on the canon?