Hi Ida,
Generally I prefer lightweight CSS frameworks, but I'm not normally the one doing the implementation. Someone on the teams I work with has already selected one, and I tend to refer to the docs as to how I'm supposed to style a button or a list or some element.
I'm not hugely keen on the frameworks that look like every other site (jQuery UI suffered from this in the past), but on the flip side of that, I do like the Material Design (and tend towards Material Lite if I'm working from scratch).
As for personally recommending, it depends on the problem. If you're prototyping, then definitely use whatever's quickest. Keep it simple if possible and try not to get too locked in to any framework.