From a NW/CO pax point of view:
B777 vs. A340/A330: B777 wins -- in addition, I like the curved interior architecture of the B777
DC9 vs. A319/A320: A319/A320 win -- it's quieter and a newer plane
DC10 vs. A330/A340: A330/A340 win -- it's a newer plane
B737 vs. A319/A320: I don't care.
B757 vs. A319/A320: B757 wins -- it's a bigger plane
B747 vs. A340/A330: B747 wins -- it's a bigger plane
B747 vs. A380: B747 wins -- A380 has too many pax -- luggage claim will be a nightmare