What are some of your favorite Dreamcast arcade-style games? They can be arcade ports or just arcade-style (like Alien Front Online). I know there are a ton of fighters ported from the Arcade but I'm going to exclude them from this thread as those are obvious (plus I'm not a big fan of fighters). Here are some of my favorites:

18 Wheeler: American Pro Trucker (Just finished the Arcade mode in this and found it to be a ton of fun! I only wish it was longer.)
Alien Front Online
Crazy Taxi
Dynamite Cop
The House of the Dead 2
Sega Bass Fishing
Sega Marine Fishing
Zombie Revenge