Don't hate me for getting Fallout 3 on Xbox 360, but I have a question.
I want to buy all of the DLC packs (bar Broken Steel, cause I already have it). I'm pretty sure it works out cheaper buying a new copy of Fallout 3 GOTY edition with the DLC, instead of buying Microsoft points and getting the DLC though the marketplace.
The thing I want to know is, how is the DLC added to your system? Is it a separate disc that installs the DLC onto your hard drive, or is it just on the disc.
And also, if I sold my copy of Fallout 3 and installed the new GOTY edition copy, would my saved games still work properly?   

Thanks man. Just what I wanted to hear. 
Thank you very much for the speedy and informative reply :)

" @Kaburorne: it comes with a second disc that you insert and choose what DLC you want and it installs to your hard drive. All save games will continue to work. "