Short bio: Computer Scientist, FOSS supporter (read more)
Tux Machines (TM)-specific
There is no dearth of good CD/DVD burning tools for Ubuntu. Brasero Disc Burner comes as default in Ubuntu and it is a good enough tool with almost all functionalities you expect from a basic CD/DVD burning application. But what really are the alternatives. Here is a quick listing of very good CD/DVD burning applications available for Linux(in no particular order). Read on.
K3B - KDE Burning Tool
K3B has been my favorite CD/DVD burning tool ever since I started using Ubuntu some 4 years ago. K3B is a Qt based application and it might look a bit out of place in Ubuntu GNOME desktop. But from a functionality point of view K3B is far ahead of all its competitors.