As long as the fabled "Radscorpions with cool sunglasses" mod remains only a dream, it's obvious no good fallout mod has ever been made.
(except for one that I heard of ages ago that added greenery and trees to the wastelands, since nature has shown to be pretty adaptive to radiation poisoning. I think there was actually a study done that showed that flora and fauna adapted better to radiation damage than to the invasive behaviors of human habitation, unsettlingly enough.)