My family had an NES and a SNES back in the late 90's, but MY first console was a Dreamcast and my first game for it was Sonic Adventure.
I still love the Dreamcast and I still love Sonic Adventure! Hell, most Dreamcast games have better graphics than most Wii games, over 10 years later. That should tell you something about the power of the Dreamcast! The only thing the system lacked, and what probably helped seal its fate, was a second thumbstick. Without it, FPS's had very awkward control schemes. For instance, Fur Fighters and MDK 2 had movement mapped to the a, b, y and x buttons. Seriously.
If it had another thumbstick, I'm 100% positive we would have seen more games on it and it would have had a much longer life than it did.