I think the breeders are quite a bit more interesting. Given the quantity of uranium on the planet is fixed, the breeder is nice because it creates more fissile material which can later be used to start another reactor. i.e. we would be able to stretch our supplies MUCH further.
http://en.wikipedia.org/wiki/Breeder_reactor

IMHO, the nukes can be more environmentally friendly as the waste can for the most part be containerized as opposed to openly dispersed into the atmosphere. IF the US and other countries would allow re-processing of spent fuel rods, the quantity of waste could be further decreased.