Best protector filter for quality lenses?

What do you reckon would be the best lens protector for a Canon 24-70 f/2.8L II (82mm thread) and a Canon 70-200 f/2.8L IS II (77mm thread)?

I've read recommendations for B+W filters, but having seen an online test of various brands/types (can't remember where), even B+W came out with flares or other optical issues compared to no protective filter at all. Obviously I'd want to avoid IQ degrading (or as little as possible), but having experienced a shattered filter in another lens which saved the lens itself I don't dare using an expensive lens without it.