My first online game was Mario Kart, too! DS version, though. Some of us have been spoiled by some of the bells and whistles of other online networks but nothing beats the pure joy of pure competition.
I've been thinking. I've been a huge endorser of Xbox Live over the years. Lately, I'm starting to think that just having someone to play with/against is enough. Anyway, this isn't about me. Glad you had a great time! Post your friend code. Maybe I'll play you someday.