I think my 5 Artoria figurines answers this question pretty well; She is without a doubt the strongest saber, and she is in my opinion the most interesting and lovable of the sabers; at least the ones that had important screen time. (I include saber lilly with Artoria, because she just is young Artoria
I also like Sakura saber a lot, she looks the best in my opinion with her red kimono, even though she isn’t the most remarkable character.
Saber of black or Siegfried is also one of my favorite characters, he has an interesting personality and is a strong hero.
The male ones from Fate/KOHA-ACE are forgettable but still, they are sabers so I like them. However, Sakura Saber is so cool it’s hard to judge; she steals all the attention.
Fox-tail saber is, as her name hints to, a fox person, which makes her quite remarkable in comparison to most other sabers, so she’s cool.
Even though saber of red is an ass, I really like this character because of what she means in the story.
The saber from Fate/Prototype really confuses me because he’s a male version of Artoria.
I won’t talk about the ones from Fate/Grand order because they do not have a story yet so I can’t really judge yet.
Huh… what to say? I really hate her. She’s such an asshole. I mean, her real identity is emperor Nero and this person was an asshole. She reflects the personality of that character pretty damn well and thus I can’t really like her. However, I like her design a lot. She has a nice dress, it doesn’t cover up her undies properly though.