As long as there's no lag, I'm fine with online play. But with games like SSBB, the lag can cause you the game, and it takes the fun out of losing too.
Kaz you're a private person? Could have fooled me man! Ha. I like both to be honest. I do play solo the majority of the time, but I have some really great memories from online play.
Offline because people take online gaming way to seriously and it just isn't fun when you make a mistake and you get scalded for it.
Even though there are some neat online games like i would love to play something like Borderlands online or something but like i said i'm very hesitant because of how serious people take online gaming now days.