The Dreamcast was a gamer's system.  Not only was it the first 128-bit system out the gate, it also built up an incredible library of games before its untimely demise.  It was really the last system to feature good 2D support for fighting games such as the Street Fighter series and SNK franchises.  It also was the only platform to carry the first Soul Calibur, arguably the best 3D fighting game of all time.