There was a shooting game that i played at a friends house. Its one of those games that you can find at an arcade. I want to say house of the dead, but i am not sure. .
Crazy Taxi
Soul Calibur
Power Stone
Skies of Arcadia
Shenmue
Seaman
Rush 2049
Those are the games I had and loved when I had a dreamcast. Make sure you get the headset for the game Seaman... because well you have to talk to the...thing