without a doubt Xukas!, the most friendly, and down to earth NPC I have ever had the pleasure to interact with. He seemed so genuine, whomever was the voice actor did a wonderful job, it's a shame we don't see him again after Murkmire.
It's a tie between Rigurt the Brash and Dringoth. Unlike so many throughout Tamriel, Rigurt actually values experiencing different cultures and were it his decision, the Three Banners War would end. There's some dialogue in which he says he questioned the point of fighting for the Ruby Throne during a banquet with King Jorunn and the next day Rigurt was sent away to commit diplomacy in some distant land. As for Dringoth, he's a well-meaning skeleton who caused a lot of trouble during his travels. He could probably share many hilarious tales if given more dialogue, for example if he became a house guest.
Imperial DK and Necro tank. PC/NA
"Nothing is so bad that it can't get any worse." (Brazilian saying)
my favorite npc in the shuts their mouth and doesnt speak, never bothers me with annoying ads, and doesnt stand in the red circle or the lava then complain about needing healed.
Caska
Seryne
Captain Jimila with her growly voice
Skordo
The two Green Ladies
Arox
Za’ji - this one just wants to giggle when he sees the pint sized captain
Queen Ayrenn: I like that she always approaches a problem from a place of giving the benefit of the doubt, and with kindness. That she doesn't take her role lightly, that she wants to earn the respect of her people, not just demand it.
Kind Emeric: I like him for the same reasons as Queen Ayrenn, but I think he is even more genuine, and shares a lot of himself with the Vestige during the Stormhaven questline.
Abnur Tharn: I didn't like him at first in the main quest; his banter with Lyris was funny, but he seemed like a traitor. That changed with the Elsweyr story, and I think he became one of the Vestige's best allies. I like his wit, that he is strategic, and that when push came to shove, he was willing to sacrifice himself (though I hope he survived, and will make a comeback).
Caska: she had great voice-acting, and I wish she had a bigger role. The dry, deadpan humor and monotone delivery, warming up to the Vestige little by little, the menacing outlook but actually really big heart were all great attributes. If we had a NPC as an adventuring companion, I'd choose Caska.
Count Verandis: one of the most well-developed and fleshed out characters, his stories were very memorable and dramatic, and I'm glad we could see his story to the end. On the flipside, I think Rada-al-Saran was a very interesting antagonist too, he should have gotten more screentime. I'm not a fan of the rest of the Ravewatch clan, although individually they are all cool (especially Adusa), but the whole vampire school thing gets a bit silly sometimes.
Valsirenn and Leythen: I like them as individual characters, because they were quite different from the NPCs the Vestige had met so far, more serious and without any comic relief, but mostly I like their shared story (even though it was sad), because it was one of the most well-written ones in the game (in general most of the characters from the CWC->Summerset arc were great).
Velidreth: she only had a small appearance in the CoS dungeon, but she is by far one of the most entertaining villains. Her dialogue and voice acting are impeccable: her bombasticness, the threatening yet confusingly seductive taunting... In a similar vein, I also like Mephala a lot.
Khunzar-ri: another truly bombastic character, and one of the rare cases where a legendary character lives up to the legend. Very well acted, and one of the most memorable encounters in Elsweyr.
Divayth Fyr: he's intelligent, serious and resourcefull, with a touch of arrogance and biting delivery (also, great voice acting). He's also a little eccentic, which makes him more interesting imo
Naryu and Melar Sadus (the scarlett judge): I wrote them together because they are both beautiful dark elves (and Naryu is also very flirty) that I'd love for romanceable companions
Rynkyus the Dremora: great voice, brave, loyal, a bit standoffish and dangerous, would also make a great romanceable companion
Tharayya: even though she only appeared in the dungeon quests, she managed to be a great character, and the adventures with her and her crew are always fun (including the ongoing one-up-manship she has with Quintus and their sarcarstic back-and-forth).
Haskill: his matter-of-fact drawl about the craziest things Uncle Sheo does, and his long-suffering countenance make for a hilarious NPC and he should definitely make more appearances (in one of them he should meet Stibbons--also, I don't know why, but I'm convinced that if Uncle Sheo failed to drive someone crazy and was driven crazy himself instead, it would be by meeting Stibbons and Lady Laurent )
There are also other characters I liked, mostly because of their involvement in their respective stories: Lyris and Sai-Sahan, Darien, Khali and Shazah, The Silvenar and the Green Lady, Xucas and the beekos from the Cyrodillic Collection, Arox, Narsis Dren (kind of awful, but hilarious), and last but not least, even though she is a fictional character herself in the literature of the game (so in a way doubly fictional), I really like Investigator Vale as well. If we are talking about characters from the Lore then my favourite is Lorkhan, and if we are talking about any characters, then it's the Vestige, and I know they are a fluid sort of character depending on the playstyle, but from 7 years of dialogue (and picking the good choices for my Vestige), they are the most lovable hero: sometimes wise-cracking and cool, sometimes goofy and shippish, but always brave, strong, willing to help, eager to travel and explore. The Vestige is truly my all-time favourite character
Oh, oh, oh...definitely the tour guide at the elden hollow wayshrine in Grahtwood! The voice actress absolutely nailed the somewhat bored, perfunctory manner. I think she does a great job and cracks me up every time.
It's strange, I really love Queen Ayrenn and Razum-Dar, they are so personable -- despite the Aldmeri Dominion being a complete trash fire, now and several ages in the future.
hopeful.heart on PC-NA/EU
"'Never love a wild thing, Mr. Bell,' Holly advised him. 'That was Doc's mistake. He was always lugging home wild things. [...] You can't give your heart to a wild thing: the more you do, the stronger they'll get. Until they're strong enough to run into the woods. Or fly into a tree. Then a taller tree. Then the sky. That's how you'll end up, Mr. Bell. If you let yourself love a wild thing. You'll end up looking at the sky.'" -- Truman Capote, Breakfast at Tiffany's.
The Thief (with honorable mentions going to The Warrior and The Mage, who sadly don’t get as much screen time); she’s friendly, helpful, sneaky, clever and her voice is adorable! On top of all of that, she’s responsible for the best plot twist in the game.