DDD is quite easilly the best debugger that I have ever used in the unix enviroment. The ability to graphically display complex data structures has saved my ass more than once, not to mention countless hours of development time. Just remember, debugging is not something that you do once development is done, this is an iterative process :)

I should also add, remember, DDD (and most other 3rd party debuggers) are just value added front ends to the already existing, maybe not so damned friendly tools!