I mostly use Dreamcast.now, pcwzrd13's schedule (although the last time I managed to play on a UK's Sunday was quite long ago) and the chat on the forum. I'm not a big fan of Discord but I find the one of DC-Talk very enjoyable.
I don't know if it's a European thing or just something typically French but I have the feeling each Dreamcast enthusiast tries to create his own little online community that only last a couple of month and then fades away. In France we had the X-Community forum, later DCman and its Discord (still very active but it seems to become more about the "man" than the DC...). A little group on the Darius-saturn forum got his hand on Xrider's custom made BBA so I guess we'll see new players on PSO, Quake III and other Toy Racers. But for how long?
My biggest regret is that only a few refer to DC-talk as a great place in order to meet other players...
I guess we lack a truly European pcwzrd13 ! A guy willing to communicate on various forums, discords etc and ready to spend some times scheduling gaming events. Thanks for your dedication pc !