My favorites are:
1. Eligos - my love for her can be explained in a simple way. I seem to latch onto some of the first characters I see in a game, and they usually become a favorite quickly. When I started playing the game, there was Hades, Eligos, and Naberius on the sides. I didn't really find Naberius or Hades attractive (Naberius looks creepy imo), maybe Eligos looked the most normal and had decent skin exposure? Whatever the case, from the first week I played I knew she would be my waifu. Too bad I only got Naberius and Titania from the 6000 starter jewels (I've later come to realize how good Titania can be). Fast forward a couple of months, to the voting thing, I put all of my SR ballot tickets towards her. She would say something along the lines of "hopefully this can bring us closer together" IIRC, and, lo and behold, from all of the premium tickets, I did get her (along with some SSRs too). The voting thing really did bring us together! Long story aside, to further the point of how I attach to characters, Yatagarasu was my first eidolon and hence she's my favorite eidolon as well (also became my first MLB one later on).
Eligos also has a nice personality (she loves the master, doesn't mind others there, so long as she can also be with him). Her scenes aren't bad either (essentially vanilla, my favorite), and she has a nice soft (?) voice. Not to mention having a sexy straightforward design.
2. Hermod - something about her design makes me like her. Not sure why, she doesn't even have the reason Eligos does for me liking her. Although her gameplay is garbage, as she literally burns herself out in autobattle.
3. Amaterasu or Gaia - I'm not sure which one I like better, but out of my four SSRs (of which I only have two elements), they are the more favorable ones of their element pair (Yamaraja is really unpleasant to me, as is Titania pre awakening). Their designs are beautiful and well done, and their gameplay contributions are pretty evident.
