UBW is my favourite too, but I do wish it had more of Illya. Rin and Archer being super prominent makes it a good route, because they're so fun to watch. Plus you get Shirou at his snarkiest, which is great. I also prefer the ending,
spoiler
I like how Shirou decides that the process of saving people is more important than the end goal, and I think that makes it more interesting than either going all in like in Fate, or abandoning it. Plus he actually starts working on his terrible mental health, which is nice.
UBW is my favourite too, but I do wish it had more of Illya. Rin and Archer being super prominent makes it a good route, because they're so fun to watch. Plus you get Shirou at his snarkiest, which is great. I also prefer the ending,
spoiler
I like how Shirou decides that the process of saving people is more important than the end goal, and I think that makes it more interesting than either going all in like in Fate, or abandoning it. Plus he actually starts working on his terrible mental health, which is nice.