Bandai doesn't even really own Dragon Ball, just the game rights, if i remember correctly.
The two most high-profile series Bandai actually OWNS are, of course, gundam, and the .hack series.
most of what bandai released in the USA, was not theirs in Japan. But there are only like 2 anime companies in Japan that will release their own stuff here. Bandai and Genon (Formerly Pioneer).
Someone asked about trigun, not sure who owns it in Japan, but in the USA Dark Horse owns rights to manga, Genon owns rights to TV series.