Well I never actually tried Xbox Live (never owned an Xbox), but I certainly don't like the idea of the monthly fee to play.
I did buy a cheap PS2 recently specifically to see where online console gaming had gone since the Dreamcast... it still boils down to the same thing:
Playing against somebody online is like playing against somebody in person, only worse.
I think Nintendo gets that... whenever you hear them talking about online they're talking about successfully recreating the experience of playing against someone in person.