Silent Scope is a Konami-made on-rails light gun shooter ported from the arcade to the Dreamcast in 2000. It's silly and fun, and kind of tricky.

One of the last official games released on the SEGA Dreamcast, Confidential Mission is a strong port of a decent (if a bit forgettable) light gun game.

The Dreamcast port of The House of the Dead 2 is one of the best (and spooookiest) light fun shooters ever made!

Virtua Cop 2, the classic arcade light gun shooter by AM2, gets a solid (but bare bones) port to the SEGA Dreamcast. This one was only released in Japan.