I have a suspicion that this was meant to get me to talk about Angel Coulby’s Guinevere in Merlin, but alas, I’ve never seen a single episode of it. If I ever do, though, that’s who it’ll be for. (In the past I would have said for Guinevere and Morgan, but I…can’t say I’ve been impressed with Katie McGrath’s acting in the few things I’ve seen her in. Unpopular opinion, I know…)
As far as adaptations go, my favorite Guineveres were probably from the movies First Knight (which may not be a particularly good movie or popular as Arthuriana, but Julia Ormond was amazing) and Camelot, and Kim Headlee’s Dawnflight. I thought Phyllis Ann Karr’s depiction of Guinevere in Idylls of the Queen was very interesting, but there we more get a perspective of her through other characters more than she’s actually on page as a character herself.
There’s always been a Madonna/whore complex in approaches to Guenevere in fiction, with Guenevere serving both roles, but the “whore” side of the equation getting an unfair share of the blame for Camelot’s downfall. A lot of Arthuriana fen-hardcore or supercasual-in my general age group having a pretty strong anti-Guenevere stance for some time due to The Mists of Avalon being so anti-Guenevere (because you can’t redeem the reputation and focus on one major female character without also tearing down another?), though that seems to have died down in recent years. While I grew up with Arthuriana adaptations going in and out of my life quite a bit, I didn’t make it to MZB until my late 20s and, well, we’ll say I don’t respect her as a person at all thanks to things that have come up over the years in regards to her and her husband, but do respect how her books brought more focus and depth to female characters in most adaptations in the last 30-odd years, but her stuff wasn’t for me, and leave it at that.
That said, I think most adaptations still don’t really “get” Guinevere, and probably don’t have much interest in doing so, even when they’re sympathetic to her, unless she actually is a central focus.. I’ll give Starz’s Camelot series a nod for trying, even if (through no fault of the actress’s) they didn’t really do a good job with her overall, but the only thing I can truly give that show good credit for is casting Eva Green and Claire Forlani as Morgan and Ygraine, and being the only adaptation I’ve encountered, outside of MZB, to bother to develop and explore Ygraine as a character and her motivations, even if it let me down in the end there to, in regards to her final fate.