There were a tonne of great shmups for Dreamcast, if you're into those sorta games. Ikaruga
come to mind as being especially awesome.
My Dreamcast model could read games that were burned onto a CD-R(*), so I actually used the console sporadically well into the late noughties. I know there were still homebrew games and arcade ports being released for the system as late as 2009
, but I'm not sure if the whole DC community is quite as active as it once was.
Nonetheless, my fondest memories of the Dreamcast is playing Chu Chu Rocket
online, which I managed to get for free by logging onto the Sega website. The console was also my first shot of the internet as well, since our family computer didn't have a modem at the time. I remember going onto the in-built chatroom and being confused about why I was being called an a/s/l.
(*) - All or most of the earlier models could, I believe. It was before they changed the colour of the spiral from orange to blue, or something like that? I don't really remember how it works. I discovered it by complete accident though.