mh, i think the n64 takes that cake.
there are a lot of shitty games for the playstation, as much as i love it. part of being sony too is that with all of it's developer loyalty, it had tomb raider, final fantasy 7 (more hype than anything else but it did sell), etc, but they also had ALL THOSE OTHER TOMB RAIDER GAMES as well as a few final fantasy duds (personally i loved 8, but it's not like most people did). The same is true for every game series made on the playstation. There is a good side to this, if tenchu had never been made, tenchu 2 would not have been either, and that game is awesome, but there's stillthe issue of tenchu sorta sucking (can i turn while running? no! can a guard see farther than a ninja? yes!). The playstations also got 6 or 7 romance of the three kingdoms games. Ape escape was great, ape escape 2......sucked hard.
The n64 on the other hand had a smaller number of good games, most of which got it right. Banjo Kazooey and Banjo Tooie are both excellent games (nearly as fun as mario 64), and SPEAKING of mario 64, IT was on the n64!. As was mario kart 64 and super smash bros. Goldeneye, Two amazing zeldas, the list goes on. When a sequel is released, most often it rocks.
clearly you can go on listing good games for both platforms (playstion has the metal gear series, which remains constantly decent, if never amazing), so i wont pretend that these few games are a "winning" argument, but imo the n64, though it's vaults are smaller, had much better quality control. They also have Shigeru Miyamoto.