Mine was (and is, since I haven't finished yet) Ajantis. It is wonderfully written, beautiful in content and made perfect sense for the PC I was roleplaying (Anne, Neutral Good Elven Sorceress).
Ever since I read the Romance guide, I was intrigued with his description and wanted to experience his story and romance in the game per se. I was not disappointed. NW: 1) spoilers follow; 2) the list is in no way complete because I haven't finished the romance yet, but I still wanted to sincerely thank the authors of the romances for this fantastic Mod.
I like that Ajantis calls my PC "Lady Anne", I find it sweet and special (i.e., something only he does). I particularly enjoyed that PC-initiated flirt about his Queen of Love and Beauty, in which he says that his choice would be "Anne of Candlekeep". (here, here and here).
I particularly liked, nay, loved, his LTs. How gradual everything is and how incredibly well developed the romance is; how my PC, should she feel so inclined, could go back and trace every little thing that made Ajantis love her, and how, when viewed in hindsight, various subtle clues foreshadow that he's falling for her. For example, there's a LT about stars and constellations which takes place at night; it ranks amongst my favourites, for its sheer beauty and romantic undertones. It is followed by a discussion next morning, which contains small details such as the fact that it takes place during Ajantis' shaving and which I like immensely precisely because of that reason and also because it's so intimate and yet innocent. Then, there's the "future" talk, in which he asks whether she'd want to continue adventuring and when he hears that she does, he sort of tries to adapt and say that unlike what he's been envisioning so far, this would be an "interesting option". Later on, there's even a follow up to the constellations discussion and I adored how this made the romance so fluid and gave it continuity.
I found it endearing that he eventually got exasperated with Anne constantly dropping her things and suggested he would walk behind her (here and here. The answer to the latter question would be of course, "Why, yes, whatever gave me away?", but alas this wasn't an option *pouts*). I liked how he looked her in the eyes when she was taking something imaginary from his cheek (here). I loved how he put his hand upon hers for the milionth time upon her pretending she was scared and how he encouraged her that she was stronger than she thought. Loved how Anne could disagree with him and he would still be interested in her (here, here and here). Wished there was more with regards to his reply at her timid compliment, but am happy with how things were overall (oh, and I wish it, oh, so much, that when he comes into SoA he'll be voiced, BTW).
Out of character (OOC), there's the small things that I can appreciate but Anne cannot, such as how the player gets the opportunity to tell him of her past beyond the usual "I was raised by Gorion" and how the options are all available until they're all selected or until the obvious "click me to skip this part" option is chosen, as opposed to how I've otherwise seen it happen (choosing one option makes all the others disappear): here, here, here and here. His connection to Keldorn: I adored that! Keldorn is one of my favourite NPCs in BG II, so in a weird way how Ajantis spoke of him made me like him even more. How polite he is ("May I tell you; "Would you tell me?"). How wonderful it is that there's an option to tell him that CHARNAME has noticed him writing letters home (makes things more natural; here); how casually it flows from that the option to ask him whether there's anyone else special to whom he's writing (here); how sweet he is in how honestly replies that he writes to his grandmother (here); how casually he asks CHARNAME to look at his family shield, which prompts a new line from him (here); how his mother wins prizes for cooking, which totally means that it's not Anne who'll do the cooking when they get married *evil grin* (here).
Oh, and I also liked the gifts he gave my PC so far, i.e., the ring and the necklace. I think it's adorable that he sends word in Waterdeep for the ring and that he somehow manages to hide the necklace till he actually gives it to her.
All in all, a superbly written romance, which, when in correlation with the other romances, gave me good, very good reasons to actually roleplay it. I mention this because in playing other Mods I did not feel as such, so it was a welcomed novelty. For example, in SoA my PC (Christine) felt no kind of moral compulsion to tell off either Anomen or Kelsey because she viewed them as merely platonic friends and certainly did not consider them romantic possibilities upon hearing most of their dialogues. Until they forced her to choose, that is. Upon which Christine felt as if she was in an alternate reality, for apart from their casual bickering with each other and an odd talk with Kelsey in which he said he watched her sleep, she had no clue either of them wanted more than friendship from her. So when they forced her to choose? Meh, she wanted to choose neither of them. Unfortunately, this was not an option.
In BG I romances, however, the story was entirely different. She tried to avoid telling off Gavin and Xan for as long as possible, because she strongly believed that conversations such as their initial LTs could happen perfectly well between friends and hated to jump to conclusions and tell them she wanted nothing more than friendship from them; oh, and she also feels guilty when she rejects people. But when it became clear that they had non-platonic feelings for her (a process which was gradual, albeit subtle), she rejected them as kindly as possible. She rejected them because even though Ajantis' LTs/flirts were even more platonic and rather void of romantic hints than theirs, she had hopes for something more and felt she would be dishonest to let someone else by her side.
OOC, this meant that even though I personally hate to let anyone in the game down, upon witnessing what refusal to tell Gavin off meant, i.e., he gave my character her first kiss, I actually reloaded (I do intend to play a game with a new PC to try his entire romance, but not this one).
BTW, I have not witnessed the Romance Conflict challenges between Ajantis/Xan/Coran. I have no idea why, is it because I picked up Coran rather late? I have, however, witnessed Xan/Gavin and Gavin/Ajantis "conflicts" which were very well done (here, here, here, here, here, here, here and here).
Finally, about voicing -- I missed it. I was accustomed to BG II (this is the first time I play BG I) and how the banters/LTs are voiced there. I got used to it, but it was still a little bit unpleasant, because it gets weird, for instance, when upon trying to talk to Ajantis/Xan/etc., CHARNAME gets the eternal "Helm! Give me strength!" / "We're all doomed". It breaks immersion, even though I know it can't be helped, bar adding voiced LTs to compensate for the repetetiveness of the "NPC selected" sounds. As a side note, it can also be funny, if one were to picture it like this (brackets stand for thoughts):
CHARNAME: (I want to talk to Xan/Ajantis etc to see how he's doing; *gets closer to one of them*) "Hello, Xan/Ajantis!"
Xan/Ajantis react to CHARNAME calling their name: (Oh, no, here she comes again) "We're all doomed!" / (Oh, no, what does she want now?) "Helm, give me strength!".
I know the reason why they weren't voiced, but I do hope that for SoA, Ajantis will get some voicing. It would make my character feel less guilty upon hearing his invoking support from his god whenever she approached him.
Anyway, I'm currently still in chapter 4 so I have more to see. I do intend to write more once I actually finish the game. But till then, I just wanted to let you all know how much I appreciate this Mod (all of it, but mostly Ajantis' romance).