Here's what I do with my lenses.

For all of my lenses, I have either NC (no color) or UV filters on them. I only use quality filters and most of them are Nikon branded NC type. As soon as I receive the lens, I inspect it and clean it if necessary, then the filter goes on. They don't come off unless I have a reason to do so.

I'm sure this thread will soon evolve into lengthy argument as it always does. I know what works for me and I stick with that.