Oh, I feel just the opposite. I loved the "filler," but usually found myself bored by the arcs. The vampire episode (the one with Mulder in the southwest, and Luke Wilson -- not the early one focusing on Scully) is one of my favorites. I think the best episodes might work as both, though -- serial and standalone -- like "Musings of a Cigarette Smoker Man" (if that's what it's called), which contributes to the mystery involving Mulder's father and the CSM, but stands beautifully on its own too. The "event" standalones (with guest-writers like King and Gibson) usually bored me too.