((o.o Did the defualt text change, Thoul?))
Honestly, I say it depends on the game at hand. With arcade games, you have to go with passwords. Because otherwise it sort of kills the fun and frustration involved with getting to that point in the game. And with Hard Drive saving (360, PS3), I only tend to like it if it's only my system.
(Long story short, there's a public place near here that has Xboxes. Unfortounately, since it's public, files get overwritten and deleted often, ensuing irritation among the more frequent goers.

)
But overall, I'll just say 'the heck with it' and go with Memory Cards. My PS2 ones have held up well over the years, and the only problem I've had with them is one more recent, and it's that I've filled up both of them.
Sony should've came out with a larger size.