San Francisco rush seems a really great Arcade conversion for the DC!
For ideas of competitions, is there anything that can be used from Sonic Adventure 1 & 2? At the end of every act you get points for how many rings you have collected etc, so would that be possible to create a competition! Also the idea of having THPS2 as a competition is fantastic! That game is pure gold! Anything from Metropolis Street Racer as well?