I have had great luck w/ ati made ati cards... they make their own where Nv does not. They are the only ones w/ the all-in-wonder too... there is a premium for an ati brand though over others. Powercolor and visiontek both have lifetime warranties for ati cards, and i just got a powercolor because of that.
Of course all lifetime warranties from anyone are for the life of the card, not your lifetime... Still a longer than normal warranty. (asus and bfg are 3 years i think, not sure about others)
Asus actually makes Nv and ati... higher price but usually bigger software package.
many of my friends have bfg and love em.
I usually buy for warranty and rep, which some have neither...