The only filter that makes sense would be a polarizer and that's due to it's special purpose. Any additional glass in the path will affect IQ. It becomes especially apparent using longer focal lengths and lenses that are already as sharp as the Hubble Space Telecope. In addition, the flat surfaces also tend to cause more internal reflections and ghosting, even ones that are multicoated. Many of Canons lenses use meniscus front lenses that are slightly curved to reduce this effect. Adding a filter on the front just defeats the engineering.
Never use a filter unless you have a specific need for it and are willing to accept some loss of IQ.