So, my best memory of the Dreamcast is getting my VGA adapter and playing some Sega Rally 2 with one of my few friends that was a Dreamcast owner when it was released. I have never seen such elation in a person playing a retro game, except when I booted up Sonic Adventure and let him play that too.
Also, the Dreamcast has arguably the best port of Crazy Taxi, and while I didn't play it there initially, I still think of the DC when I think of Crazy Taxi, which happens to be one of my favorite arcade games of all time. It's also home to Jet Grind Radio, which is basically just cool.
I guess even somebody who doesn't like the system that much like myself can't help but think of the thing fondly in memory.
Related: I remember when I was 7, my father asked me if I wanted the new Sega or the PlayStation 2 in the car. Ended up getting a PS2 at launch.
Older. Not wiser.