I just gave one of these to my son as I've sold my freeride bike and decided to act (and maybe try to look) my age:
Your face will thank you in event of a plant

I'm sure my sons face is in need of protecting rather than my old sorry one so I'm just using a cheap Bell I bought from Decathlon. It's not bad but sits a bit high on the head. I'd try on as many as possible and not order online first because they do look different when worn depending on head shape.