I've compared all my filters side by side, and in a flare inducing situation, even a cheap multicoated filter will do better than any single-coated or uncoated filter. Resin filters, interestingly enough, seem better than single coated filters as far as flare and ghosting is concerned.

I don't use protective filters unless there is an obvious hazard, though I do use UV filters (or sometimes something stronger) with color film to filter UV.

The best filters being made today are Heliopan and B+W in their multicoated versions.