I like small knives and most of my favorite knives are small, some are objectively small and some subjectively small but small in some way nonetheless.
Being small or relatively small is what first drew me to them, and other factors like their aesthetic their covers their ergonomics and their functionality led to them becoming favorites.
My favorite Buck model is the 305 because of it's size, and blade configuration.

These 3 are my favorites for their covers, W&T, and their very consistently ground edges.
The '89 sambar stag example in the middle was also the most expensive hardest to acquire of all my 305's, aside from having gorgeous covers acquiring it felt the most like an achievement.
The Case 08 half whittler is my favorite Case model for it's size mostly, but I also like the aesthetic.
This is my favorite 08 as a user, for it's CV blades.

In some ways I like this one better, the bolsters and covers are rounded more which I prefer.
It is also a special knife because Case themselves contributed it to a special giveaway that I won here on the porch.
All of my favorites run the gamut of reasons of why they're favorites.