I personally prefer Bootstrap to Tailwind, but my favorite is https://picocss.com/

Usually, I just want decent-looking default CSS styles. The benefits of a CSS framework have diminishing returns when using frameworks with styles scoped to components (like SvelteKit/Vue/React).

The fact Tailwind removes all styles so you can't even tell a button is a button unless you add classes is annoying. If you know the class names, sometimes it's a little more convenient to add Tailwind classes, but for the most part it just clutters the HTML. And it makes it difficult to update entire "classes" of elements: you have to update each element one at a time.

Nice, first time I hear about picocss
I think picocss is the best classless CSS framework, but there are a bunch of others:

https://github.com/dohliam/dropin-minimal-css