I'd like to recommend "Doctor, Copper, Sailor, Corpse", by Scarlet Baldy (http://fluky.gossamer.org/author/13064-1.html). I can't get enough of this fic and I haven't seen it recommended in other sites: it's set in season 8, and it's a brilliant take on the events before, during and after Mulder's 'death'. Just check out the summary:

This little piggy rots in his coffin, this little piggy is showing, this little piggy is a good partner, this little piggy is hovering, and all the little Hoover piggies are snickering all the way home.